Remove feature gates for if let, while let, and tuple indexing

Closes #19469

src/test/compile-fail/borrow-tuple-fields.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 struct Foo(Box<int>, int);
 
 struct Bar(int, int);

src/test/compile-fail/if-let.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(macro_rules,if_let)]
+#![feature(macro_rules)]
 
 fn macros() {
     macro_rules! foo{

src/test/compile-fail/issue-18566.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 struct MyPtr<'a>(&'a mut uint);
 impl<'a> Deref<uint> for MyPtr<'a> {
     fn deref<'b>(&'b self) -> &'b uint { self.0 }

src/test/compile-fail/issue-19244-1.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 const TUP: (uint,) = (42,);
 
 fn main() {

src/test/compile-fail/lint-unnecessary-parens.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 #![deny(unused_parens)]
-#![feature(if_let,while_let)]
 
 #[deriving(Eq, PartialEq)]
 struct X { y: bool }

src/test/compile-fail/move-fragments-1.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 // Test that we correctly compute the move fragments for a fn.
 //
 // Note that the code below is not actually incorrect; the

src/test/compile-fail/move-out-of-tuple-field.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 struct Foo(Box<int>);
 
 fn main() {

src/test/compile-fail/tuple-index-not-tuple.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 struct Point { x: int, y: int }
 struct Empty;
 

src/test/compile-fail/tuple-index-out-of-bounds.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tuple_indexing)]
-
 struct Point(int, int);
 
 fn main() {

src/test/compile-fail/while-let.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(macro_rules,while_let)]
+#![feature(macro_rules)]
 
 fn macros() {
     macro_rules! foo{