Cleanup the stray comments and variables I could dig out of Sema to
refer to 'expansion' instead of 'instantiation'.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136060 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 32d90bf..f86133a 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -3067,11 +3067,11 @@
   if (Source == Target) return;
   if (Target->isDependentType()) return;
 
-  // If the conversion context location is invalid don't complain.
-  // We also don't want to emit a warning if the issue occurs from the
-  // instantiation of a system macro.  The problem is that 'getSpellingLoc()'
-  // is slow, so we delay this check as long as possible.  Once we detect
-  // we are in that scenario, we just return.
+  // If the conversion context location is invalid don't complain. We also
+  // don't want to emit a warning if the issue occurs from the expansion of
+  // a system macro. The problem is that 'getSpellingLoc()' is slow, so we
+  // delay this check as long as possible. Once we detect we are in that
+  // scenario, we just return.
   if (CC.isInvalid())
     return;