COFF: Let globals with private linkage reside in their own section

COFF COMDATs (for selection kinds other than 'select any') require at
least one non-section symbol in the symbol table.
Satisfy this by morally enhancing the linkage from private to internal.

Differential Revision: http://reviews.llvm.org/D8394

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232570 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/TargetLoweringObjectFile.cpp

@@ -343,3 +343,9 @@ const MCExpr *TargetLoweringObjectFile::getDebugThreadLocalSymbol(const MCSymbol
   // null return could mean 'no location' & we should just do that here.
   return MCSymbolRefExpr::Create(Sym, *Ctx);
 }
+
+void TargetLoweringObjectFile::getNameWithPrefix(
+    SmallVectorImpl<char> &OutName, const GlobalValue *GV,
+    bool CannotUsePrivateLabel, Mangler &Mang, const TargetMachine &TM) const {
+  Mang.getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
+}