Cleanup handling of UniqueExternalLinkage.

This patch renames getLinkage to getLinkageInternal. Only code that
needs to handle UniqueExternalLinkage specially should call this.

Linkage, as defined in the c++ standard, is provided by
getFormalLinkage. It maps UniqueExternalLinkage to ExternalLinkage.

Most places in the compiler actually want isExternallyVisible, which
handles UniqueExternalLinkage as internal.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181677 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index b9695cc..7f1def7 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -3793,14 +3793,14 @@
   }
 
   // Address / reference template args must have external linkage in C++98.
-  if (Entity->getLinkage() == InternalLinkage) {
+  if (Entity->getFormalLinkage() == InternalLinkage) {
     S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ?
              diag::warn_cxx98_compat_template_arg_object_internal :
              diag::ext_template_arg_object_internal)
       << !Func << Entity << Arg->getSourceRange();
     S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
       << !Func;
-  } else if (Entity->getLinkage() == NoLinkage) {
+  } else if (!Entity->hasLinkage()) {
     S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
       << !Func << Entity << Arg->getSourceRange();
     S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)