hygiene for for loops, if let, while let

and some unrelated test cleanups

src/test/compile-fail/for-expn-2.rs

@@ -1,18 +0,0 @@
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// Test that we get an expansion stack for `for` loops.
-
-// error-pattern:in this expansion of for loop expansion
-
-fn main() {
-    for t in &foo {
-    }
-}

src/test/compile-fail/for-loop-refutable-pattern-error-message.rs

@@ -9,7 +9,5 @@
 // except according to those terms.
 
 fn main() {
-    for
-        &1 //~ ERROR refutable pattern in `for` loop binding
-        in [1].iter() {}
+    for &1 in [1].iter() {} //~ ERROR refutable pattern in `for` loop binding
 }

src/test/compile-fail/issue-15167.rs

@@ -16,4 +16,17 @@ fn main() -> (){
     for n in 0..1 {
         println!("{}", f!()); //~ ERROR unresolved name `n`
     }
+
+    if let Some(n) = None {
+        println!("{}", f!()); //~ ERROR unresolved name `n`
+    }
+
+    if false {
+    } else if let Some(n) = None {
+        println!("{}", f!()); //~ ERROR unresolved name `n`
+    }
+
+    while let Some(n) = None {
+        println!("{}", f!()); //~ ERROR unresolved name `n`
+    }
 }

src/test/compile-fail/issue-15381.rs

@@ -13,10 +13,8 @@
 fn main() {
     let values: Vec<u8> = vec![1,2,3,4,5,6,7,8];
 
-    for
-        [x,y,z]
-//~^ ERROR refutable pattern in `for` loop binding: `[]` not covered
-        in values.chunks(3).filter(|&xs| xs.len() == 3) {
+    for [x,y,z] in values.chunks(3).filter(|&xs| xs.len() == 3) {
+        //~^ ERROR refutable pattern in `for` loop binding: `[]` not covered
         println!("y={}", y);
     }
 }