DebugInfo: Pass MCSymbolRefExprs for labels instead of MCSymbols

This is a precursor to adding debug info support for TLS which requires
non-default relocations applied to TLS symbols.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185202 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index a954eae..ead90c0 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1918,9 +1918,9 @@
     case dwarf::DW_AT_location: {
       if (DIELabel *L = dyn_cast<DIELabel>(Values[i])) {
         if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
-          Asm->EmitLabelReference(L->getValue(), 4);
+          Asm->EmitLabelReference(&L->getValue()->getSymbol(), 4);
         else
-          Asm->EmitLabelDifference(L->getValue(), DwarfDebugLocSectionSym, 4);
+          Asm->EmitLabelDifference(&L->getValue()->getSymbol(), DwarfDebugLocSectionSym, 4);
       } else {
         Values[i]->EmitValue(Asm, Form);
       }