[DebugInfo] Allow getDebugThreadLocalSymbol to return MCExpr

This allows getDebugThreadLocalSymbol to return a generic MCExpr
instead of just a MCSymbolRefExpr.

This is in preparation for supporting debug info for TLS variables
on PowerPC, where we need to describe the variable location using
a more complex expression than just MCSymbolRefExpr.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index fc50aa5..cd810b6 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -318,7 +318,7 @@
   }
 }
 
-const MCSymbolRefExpr *TargetLoweringObjectFile::getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
+const MCExpr *TargetLoweringObjectFile::getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
   // FIXME: It's not clear what, if any, default this should have - perhaps a
   // null return could mean 'no location' & we should just do that here.
   return MCSymbolRefExpr::Create(Sym, *Ctx);