Provide isConst/Volatile on CXXMethodDecl.

This also provides isConst/Volatile/Restrict on FunctionTypes to coalesce
the implementation with other callers (& update those other callers).

Patch contributed by Sam Panzer (panzer@google.com).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161647 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index bb08405..2e099e9 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -2369,11 +2369,11 @@
 
   // Handle multiple qualifiers.
   std::string QualsStr;
-  if (Proto->getTypeQuals() & Qualifiers::Const)
+  if (Proto->isConst())
     QualsStr += " const";
-  if (Proto->getTypeQuals() & Qualifiers::Volatile)
+  if (Proto->isVolatile())
     QualsStr += " volatile";
-  if (Proto->getTypeQuals() & Qualifiers::Restrict)
+  if (Proto->isRestrict())
     QualsStr += " restrict";
   Result.AddInformativeChunk(Result.getAllocator().CopyString(QualsStr));
 }