Clean up as many of the comments in Basic I can find to talk in terms of
'expansion' rather than 'instantiation' for macro source locations.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136058 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index 08e4420..fbeec27 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -704,8 +704,8 @@
   }
 
   // If we have any Fix-Its, make sure that all of the Fix-Its point into
-  // source locations that aren't macro instantiations. If any point into
-  // macro instantiations, remove all of the Fix-Its.
+  // source locations that aren't macro expansions. If any point into macro
+  // expansions, remove all of the Fix-Its.
   for (unsigned I = 0, N = Diag.NumFixItHints; I != N; ++I) {
     const FixItHint &FixIt = Diag.FixItHints[I];
     if (FixIt.RemoveRange.isInvalid() ||