diff --git a/src/librustc_target/spec/armebv7r_none_eabi.rs b/src/librustc_target/spec/armebv7r_none_eabi.rs
index 3a5957892b59..ebe901e4f274 100644
--- a/src/librustc_target/spec/armebv7r_none_eabi.rs
+++ b/src/librustc_target/spec/armebv7r_none_eabi.rs
@@ -1,7 +1,6 @@
 // Targets the Big endian Cortex-R4/R5 processor (ARMv7-R)
 
 use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions, TargetResult};
-use std::default::Default;
 
 pub fn target() -> TargetResult {
     Ok(Target {
diff --git a/src/librustc_target/spec/armebv7r_none_eabihf.rs b/src/librustc_target/spec/armebv7r_none_eabihf.rs
index 9f95a1a6f44f..8652d1051ad0 100644
--- a/src/librustc_target/spec/armebv7r_none_eabihf.rs
+++ b/src/librustc_target/spec/armebv7r_none_eabihf.rs
@@ -1,7 +1,6 @@
 // Targets the Cortex-R4F/R5F processor (ARMv7-R)
 
 use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions, TargetResult};
-use std::default::Default;
 
 pub fn target() -> TargetResult {
     Ok(Target {
diff --git a/src/librustc_target/spec/armv7r_none_eabi.rs b/src/librustc_target/spec/armv7r_none_eabi.rs
index 517368e6a23e..b7fcda63db00 100644
--- a/src/librustc_target/spec/armv7r_none_eabi.rs
+++ b/src/librustc_target/spec/armv7r_none_eabi.rs
@@ -1,7 +1,6 @@
 // Targets the Little-endian Cortex-R4/R5 processor (ARMv7-R)
 
 use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions, TargetResult};
-use std::default::Default;
 
 pub fn target() -> TargetResult {
     Ok(Target {
diff --git a/src/librustc_target/spec/armv7r_none_eabihf.rs b/src/librustc_target/spec/armv7r_none_eabihf.rs
index 6363469d9292..340090fd43b7 100644
--- a/src/librustc_target/spec/armv7r_none_eabihf.rs
+++ b/src/librustc_target/spec/armv7r_none_eabihf.rs
@@ -1,7 +1,6 @@
 // Targets the Little-endian Cortex-R4F/R5F processor (ARMv7-R)
 
 use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions, TargetResult};
-use std::default::Default;
 
 pub fn target() -> TargetResult {
     Ok(Target {
diff --git a/src/librustc_target/spec/dragonfly_base.rs b/src/librustc_target/spec/dragonfly_base.rs
index e26d0ae50b26..c7062e1ca519 100644
--- a/src/librustc_target/spec/dragonfly_base.rs
+++ b/src/librustc_target/spec/dragonfly_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args = LinkArgs::new();
diff --git a/src/librustc_target/spec/freebsd_base.rs b/src/librustc_target/spec/freebsd_base.rs
index fc252b6d43d2..d2a087ab62f9 100644
--- a/src/librustc_target/spec/freebsd_base.rs
+++ b/src/librustc_target/spec/freebsd_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args = LinkArgs::new();
diff --git a/src/librustc_target/spec/fuchsia_base.rs b/src/librustc_target/spec/fuchsia_base.rs
index 046388e9be8f..4060b126cddb 100644
--- a/src/librustc_target/spec/fuchsia_base.rs
+++ b/src/librustc_target/spec/fuchsia_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut pre_link_args = LinkArgs::new();
diff --git a/src/librustc_target/spec/haiku_base.rs b/src/librustc_target/spec/haiku_base.rs
index 1ddab7be180e..3d7ae6c302d9 100644
--- a/src/librustc_target/spec/haiku_base.rs
+++ b/src/librustc_target/spec/haiku_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     TargetOptions {
diff --git a/src/librustc_target/spec/hermit_base.rs b/src/librustc_target/spec/hermit_base.rs
index 3f9dad689fd5..b9f94023e7a7 100644
--- a/src/librustc_target/spec/hermit_base.rs
+++ b/src/librustc_target/spec/hermit_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, PanicStrategy, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut pre_link_args = LinkArgs::new();
diff --git a/src/librustc_target/spec/hermit_kernel_base.rs b/src/librustc_target/spec/hermit_kernel_base.rs
index 650219c21ac4..1f9b195e2e69 100644
--- a/src/librustc_target/spec/hermit_kernel_base.rs
+++ b/src/librustc_target/spec/hermit_kernel_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, PanicStrategy, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut pre_link_args = LinkArgs::new();
diff --git a/src/librustc_target/spec/l4re_base.rs b/src/librustc_target/spec/l4re_base.rs
index b712dcae8997..5caad10161d8 100644
--- a/src/librustc_target/spec/l4re_base.rs
+++ b/src/librustc_target/spec/l4re_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, PanicStrategy, TargetOptions};
-use std::default::Default;
 //use std::process::Command;
 
 // Use GCC to locate code for crt* libraries from the host, not from L4Re. Note
diff --git a/src/librustc_target/spec/linux_base.rs b/src/librustc_target/spec/linux_base.rs
index a5d7f8e07c44..52892fc35924 100644
--- a/src/librustc_target/spec/linux_base.rs
+++ b/src/librustc_target/spec/linux_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args = LinkArgs::new();
diff --git a/src/librustc_target/spec/linux_kernel_base.rs b/src/librustc_target/spec/linux_kernel_base.rs
index fae44836fa82..4a900d1b02cb 100644
--- a/src/librustc_target/spec/linux_kernel_base.rs
+++ b/src/librustc_target/spec/linux_kernel_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, PanicStrategy, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut pre_link_args = LinkArgs::new();
diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
index d29b1dcdf8a4..d0129b2cdd37 100644
--- a/src/librustc_target/spec/mod.rs
+++ b/src/librustc_target/spec/mod.rs
@@ -37,7 +37,6 @@
 use crate::spec::abi::{lookup as lookup_abi, Abi};
 use rustc_serialize::json::{Json, ToJson};
 use std::collections::BTreeMap;
-use std::default::Default;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
 use std::{fmt, io};
diff --git a/src/librustc_target/spec/netbsd_base.rs b/src/librustc_target/spec/netbsd_base.rs
index eb359b920463..95c4749f9c74 100644
--- a/src/librustc_target/spec/netbsd_base.rs
+++ b/src/librustc_target/spec/netbsd_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args = LinkArgs::new();
diff --git a/src/librustc_target/spec/openbsd_base.rs b/src/librustc_target/spec/openbsd_base.rs
index b66c56e1a7ae..cadd14df6935 100644
--- a/src/librustc_target/spec/openbsd_base.rs
+++ b/src/librustc_target/spec/openbsd_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args = LinkArgs::new();
diff --git a/src/librustc_target/spec/redox_base.rs b/src/librustc_target/spec/redox_base.rs
index 6398fa91f025..18cafe654d17 100644
--- a/src/librustc_target/spec/redox_base.rs
+++ b/src/librustc_target/spec/redox_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args = LinkArgs::new();
diff --git a/src/librustc_target/spec/solaris_base.rs b/src/librustc_target/spec/solaris_base.rs
index 98a2a0fbc9cc..8d3a3563f416 100644
--- a/src/librustc_target/spec/solaris_base.rs
+++ b/src/librustc_target/spec/solaris_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::TargetOptions;
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     TargetOptions {
diff --git a/src/librustc_target/spec/thumb_base.rs b/src/librustc_target/spec/thumb_base.rs
index 99ab996be959..eca095b59428 100644
--- a/src/librustc_target/spec/thumb_base.rs
+++ b/src/librustc_target/spec/thumb_base.rs
@@ -28,7 +28,6 @@
 // build scripts / gcc flags.
 
 use crate::spec::{PanicStrategy, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     // See rust-lang/rfcs#1645 for a discussion about these defaults
diff --git a/src/librustc_target/spec/uefi_msvc_base.rs b/src/librustc_target/spec/uefi_msvc_base.rs
index 6f5e1badfb66..148658f4abb9 100644
--- a/src/librustc_target/spec/uefi_msvc_base.rs
+++ b/src/librustc_target/spec/uefi_msvc_base.rs
@@ -10,7 +10,6 @@
 // code runs in the same environment, no process separation is supported.
 
 use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, PanicStrategy, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let pre_link_args_msvc = vec![
diff --git a/src/librustc_target/spec/vxworks_base.rs b/src/librustc_target/spec/vxworks_base.rs
index 1763c9139b1b..1b25c51278d4 100644
--- a/src/librustc_target/spec/vxworks_base.rs
+++ b/src/librustc_target/spec/vxworks_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut args_crt = LinkArgs::new();
diff --git a/src/librustc_target/spec/windows_gnu_base.rs b/src/librustc_target/spec/windows_gnu_base.rs
index 097ee09f1ea8..33ecb1d0d48c 100644
--- a/src/librustc_target/spec/windows_gnu_base.rs
+++ b/src/librustc_target/spec/windows_gnu_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut pre_link_args = LinkArgs::new();
diff --git a/src/librustc_target/spec/windows_msvc_base.rs b/src/librustc_target/spec/windows_msvc_base.rs
index dc56dd916ff0..328cdec5492e 100644
--- a/src/librustc_target/spec/windows_msvc_base.rs
+++ b/src/librustc_target/spec/windows_msvc_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let pre_link_args_msvc = vec!["/NOLOGO".to_string(), "/NXCOMPAT".to_string()];
diff --git a/src/librustc_target/spec/windows_uwp_gnu_base.rs b/src/librustc_target/spec/windows_uwp_gnu_base.rs
index f19bd10dc0bb..bd1e0bc5eba9 100644
--- a/src/librustc_target/spec/windows_uwp_gnu_base.rs
+++ b/src/librustc_target/spec/windows_uwp_gnu_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let mut pre_link_args = LinkArgs::new();
diff --git a/src/librustc_target/spec/windows_uwp_msvc_base.rs b/src/librustc_target/spec/windows_uwp_msvc_base.rs
index 2c70ba7abe26..3372da857fee 100644
--- a/src/librustc_target/spec/windows_uwp_msvc_base.rs
+++ b/src/librustc_target/spec/windows_uwp_msvc_base.rs
@@ -1,5 +1,4 @@
 use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, TargetOptions};
-use std::default::Default;
 
 pub fn opts() -> TargetOptions {
     let pre_link_args_msvc = vec![