Report special messages for path segment keywords in wrong positions

src/test/compile-fail/dollar-crate-is-keyword-2.rs

@@ -13,8 +13,8 @@ mod a {}
 macro_rules! m {
     () => {
         use a::$crate; //~ ERROR unresolved import `a::$crate`
-        use a::$crate::b; //~ ERROR unresolved import `a::$crate`
-        type A = a::$crate; //~ ERROR cannot find type `$crate` in module `a`
+        use a::$crate::b; //~ ERROR `$crate` in paths can only be used in start position
+        type A = a::$crate; //~ ERROR `$crate` in paths can only be used in start position
     }
 }
 

src/test/compile-fail/rfc-2126-crate-paths/crate-path-non-absolute.rs

@@ -14,7 +14,7 @@ struct S;
 
 mod m {
     fn f() {
-        let s = crate::S; //~ ERROR undeclared type or module `crate`
+        let s = crate::S; //~ ERROR `crate` can only be used in absolute paths
     }
 }
 

src/test/compile-fail/rfc-2126-crate-paths/crate-visibility-ambiguity.rs

@@ -15,7 +15,7 @@ mod m {
     pub struct Z;
     pub struct S1(crate (::m::Z)); // OK
     pub struct S2(::crate ::m::Z); // OK
-    pub struct S3(crate ::m::Z); //~ ERROR undeclared type or module `crate`
+    pub struct S3(crate ::m::Z); //~ ERROR `crate` can only be used in absolute paths
 }
 
 fn main() {

src/test/compile-fail/rfc-2126-crate-paths/keyword-crate-as-identifier.rs

@@ -11,5 +11,5 @@
 #![feature(crate_in_paths)]
 
 fn main() {
-    let crate = 0; //~ ERROR cannot find unit struct/variant or constant `crate` in this scope
+    let crate = 0; //~ ERROR `crate` can only be used in absolute paths
 }

src/test/compile-fail/super-at-top-level.rs

@@ -8,8 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use super::f; //~ ERROR unresolved import `super` [E0432]
-              //~^ There are too many initial `super`s.
+use super::f; //~ ERROR There are too many initial `super`s
 
 fn main() {
 }

src/test/compile-fail/use-super-global-path.rs

@@ -14,11 +14,11 @@ struct S;
 struct Z;
 
 mod foo {
-    use ::super::{S, Z}; //~ ERROR unresolved import `super`
+    use ::super::{S, Z}; //~ ERROR global paths cannot start with `super`
 
     pub fn g() {
-        use ::super::main; //~ ERROR unresolved import `super`
-        main();
+        use ::super::main; //~ ERROR global paths cannot start with `super`
+        main(); //~ ERROR cannot find function `main` in this scope
     }
 }