Convert SemaTemplate*.cpp to pass a callback object to CorrectTypo.

The change to SemaTemplateVariadic.cpp improves the typo correction
results in certain situations, while the change to SemaTemplate.cpp
does not change existing behavior.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148155 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 6c2a94a..d8aab82 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -301,10 +301,15 @@
     // If we did not find any names, attempt to correct any typos.
     DeclarationName Name = Found.getLookupName();
     Found.clear();
+    // Simple filter callback that, for keywords, only accepts the C++ *_cast
+    CorrectionCandidateCallback FilterCCC;
+    FilterCCC.WantTypeSpecifiers = false;
+    FilterCCC.WantExpressionKeywords = false;
+    FilterCCC.WantRemainingKeywords = false;
+    FilterCCC.WantCXXNamedCasts = true;
     if (TypoCorrection Corrected = CorrectTypo(Found.getLookupNameInfo(),
                                                Found.getLookupKind(), S, &SS,
-                                               LookupCtx, false,
-                                               CTC_CXXCasts)) {
+                                               &FilterCCC, LookupCtx)) {
       Found.setLookupName(Corrected.getCorrection());
       if (Corrected.getCorrectionDecl())
         Found.addDecl(Corrected.getCorrectionDecl());