Do not suggest using -Zmacro-backtrace for builtin macros

For macros that are implemented on the compiler, we do *not* mention the `-Zmacro-backtrace` flag. This includes `derive`s and standard macros.

compiler/rustc_span/src/hygiene.rs

@@ -982,6 +982,8 @@ pub struct ExpnData {
     /// Should debuginfo for the macro be collapsed to the outermost expansion site (in other
     /// words, was the macro definition annotated with `#[collapse_debuginfo]`)?
     pub(crate) collapse_debuginfo: bool,
+    /// When true, we do not display the note telling people to use the `-Zmacro-backtrace` flag.
+    pub hide_backtrace: bool,
 }
 
 impl !PartialEq for ExpnData {}
@@ -1000,6 +1002,7 @@ impl ExpnData {
         allow_internal_unsafe: bool,
         local_inner_macros: bool,
         collapse_debuginfo: bool,
+        hide_backtrace: bool,
     ) -> ExpnData {
         ExpnData {
             kind,
@@ -1014,6 +1017,7 @@ impl ExpnData {
             allow_internal_unsafe,
             local_inner_macros,
             collapse_debuginfo,
+            hide_backtrace,
         }
     }
 
@@ -1038,6 +1042,7 @@ impl ExpnData {
             allow_internal_unsafe: false,
             local_inner_macros: false,
             collapse_debuginfo: false,
+            hide_backtrace: false,
         }
     }