Sema: Don't crash when specializing a global scope function in a class

We assumed that class-scope specializations would result in a
CXXMethodDecl for that class.  However, globally qualified functions
will result in normal FunctionDecls.

llvm-svn: 225508
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 8a50475..1e20121 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -7482,7 +7482,7 @@
     } else if (isFunctionTemplateSpecialization) {
       if (CurContext->isDependentContext() && CurContext->isRecord() 
           && !isFriend) {
-        isDependentClassScopeExplicitSpecialization = true;
+        isDependentClassScopeExplicitSpecialization = isa<CXXMethodDecl>(NewFD);
         Diag(NewFD->getLocation(), getLangOpts().MicrosoftExt ? 
           diag::ext_function_specialization_in_class :
           diag::err_function_specialization_in_class)