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/ARCMigrate/Transforms.cpp b/lib/ARCMigrate/Transforms.cpp
index 0872195..6c724af 100644
--- a/lib/ARCMigrate/Transforms.cpp
+++ b/lib/ARCMigrate/Transforms.cpp
@@ -94,7 +94,7 @@
       if (FD->isGlobal() &&
           FD->getIdentifier() &&
           FD->getParent()->isTranslationUnit() &&
-          FD->hasExternalLinkage() &&
+          FD->isExternallyVisible() &&
           ento::cocoa::isRefType(callE->getType(), "CF",
                                  FD->getIdentifier()->getName())) {
         StringRef fname = FD->getIdentifier()->getName();
@@ -198,7 +198,7 @@
   E = E->IgnoreParenCasts();
   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
     return DRE->getDecl()->getDeclContext()->isFileContext() &&
-           DRE->getDecl()->hasExternalLinkage();
+           DRE->getDecl()->isExternallyVisible();
   if (ConditionalOperator *condOp = dyn_cast<ConditionalOperator>(E))
     return isGlobalVar(condOp->getTrueExpr()) &&
            isGlobalVar(condOp->getFalseExpr());