Suppress the macro backtrace for fileline_note and fileline_help.

Author: rprichard

src/libsyntax/codemap.rs

@@ -871,7 +871,7 @@ impl CodeMap {
         F: FnOnce(Option<&ExpnInfo>) -> T,
     {
         match id {
-            NO_EXPANSION => f(None),
+            NO_EXPANSION | COMMAND_LINE_EXPN => f(None),
             ExpnId(i) => f(Some(&(*self.expansions.borrow())[i as usize]))
         }
     }

src/libsyntax/diagnostic.rs

@@ -465,22 +465,21 @@ fn emit(dst: &mut EmitterWriter, cm: &codemap::CodeMap, rsp: RenderSpan,
     match rsp {
         FullSpan(_) => {
             try!(highlight_lines(dst, cm, sp, lvl, cm.span_to_lines(sp)));
+            try!(print_macro_backtrace(dst, cm, sp));
         }
         EndSpan(_) => {
             try!(end_highlight_lines(dst, cm, sp, lvl, cm.span_to_lines(sp)));
+            try!(print_macro_backtrace(dst, cm, sp));
         }
         Suggestion(_, ref suggestion) => {
             try!(highlight_suggestion(dst, cm, sp, suggestion));
+            try!(print_macro_backtrace(dst, cm, sp));
         }
         FileLine(..) => {
             // no source text in this case!
         }
     }
 
-    if sp != COMMAND_LINE_SP {
-        try!(print_macro_backtrace(dst, cm, sp));
-    }
-
     match code {
         Some(code) =>
             match dst.registry.as_ref().and_then(|registry| registry.find_description(code)) {