Move getSymbol to TargetLoweringObjectFile.

This allows constructing a Mangler with just a TargetMachine.

llvm-svn: 193630
diff --git a/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp b/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
index dfdf6ab..7ec71b2 100644
--- a/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
@@ -47,7 +47,7 @@
                         MCStreamer &Streamer) const {
   assert(Encoding == DW_EH_PE_absptr && "Can handle absptr encoding only");
 
-  return MCSymbolRefExpr::Create(Mang->getSymbol(GV),
+  return MCSymbolRefExpr::Create(getSymbol(*Mang, GV),
                                  MCSymbolRefExpr::VK_ARM_TARGET2,
                                  getContext());
 }