Pass DebugLoc and SDLoc by const ref.

This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.

llvm-svn: 272512
diff --git a/llvm/lib/Target/X86/X86SelectionDAGInfo.h b/llvm/lib/Target/X86/X86SelectionDAGInfo.h
index 828243c..f4a285a 100644
--- a/llvm/lib/Target/X86/X86SelectionDAGInfo.h
+++ b/llvm/lib/Target/X86/X86SelectionDAGInfo.h
@@ -32,18 +32,15 @@
 public:
   explicit X86SelectionDAGInfo() = default;
 
-  SDValue EmitTargetCodeForMemset(SelectionDAG &DAG, SDLoc dl,
-                                  SDValue Chain,
-                                  SDValue Dst, SDValue Src,
-                                  SDValue Size, unsigned Align,
-                                  bool isVolatile,
+  SDValue EmitTargetCodeForMemset(SelectionDAG &DAG, const SDLoc &dl,
+                                  SDValue Chain, SDValue Dst, SDValue Src,
+                                  SDValue Size, unsigned Align, bool isVolatile,
                                   MachinePointerInfo DstPtrInfo) const override;
 
-  SDValue EmitTargetCodeForMemcpy(SelectionDAG &DAG, SDLoc dl,
-                                  SDValue Chain,
-                                  SDValue Dst, SDValue Src,
-                                  SDValue Size, unsigned Align,
-                                  bool isVolatile, bool AlwaysInline,
+  SDValue EmitTargetCodeForMemcpy(SelectionDAG &DAG, const SDLoc &dl,
+                                  SDValue Chain, SDValue Dst, SDValue Src,
+                                  SDValue Size, unsigned Align, bool isVolatile,
+                                  bool AlwaysInline,
                                   MachinePointerInfo DstPtrInfo,
                                   MachinePointerInfo SrcPtrInfo) const override;
 };