Sort MultiSpans on creation

Author: estebank

src/librustc_span/lib.rs

@@ -657,7 +657,8 @@ impl MultiSpan {
         MultiSpan { primary_spans: vec![primary_span], span_labels: vec![] }
     }
 
-    pub fn from_spans(vec: Vec<Span>) -> MultiSpan {
+    pub fn from_spans(mut vec: Vec<Span>) -> MultiSpan {
+        vec.sort();
         MultiSpan { primary_spans: vec, span_labels: vec![] }
     }
 

src/test/ui/specialization/defaultimpl/validation.stderr

@@ -25,13 +25,13 @@ LL | default impl !Send for Z {}
    | default because of this
 
 error[E0750]: negative impls cannot be default impls
-  --> $DIR/validation.rs:10:14
+  --> $DIR/validation.rs:10:1
    |
 LL | default impl !Send for Z {}
    | ^^^^^^^      ^
 
 error[E0750]: negative impls cannot be default impls
-  --> $DIR/validation.rs:14:14
+  --> $DIR/validation.rs:14:1
    |
 LL | default impl !Tr for S {}
    | ^^^^^^^      ^

src/test/ui/traits/negative-impls/negative-default-impls.stderr

@@ -1,5 +1,5 @@
 error[E0750]: negative impls cannot be default impls
-  --> $DIR/negative-default-impls.rs:8:14
+  --> $DIR/negative-default-impls.rs:8:1
    |
 LL | default impl !MyTrait for u32 {}
    | ^^^^^^^      ^