Implement a bunch more TargetSelectionDAGInfo infrastructure.

Move EmitTargetCodeForMemcpy, EmitTargetCodeForMemset, and
EmitTargetCodeForMemmove out of TargetLowering and into
SelectionDAGInfo to exercise this.

llvm-svn: 103481
diff --git a/llvm/lib/Target/Mips/MipsSelectionDAGInfo.h b/llvm/lib/Target/Mips/MipsSelectionDAGInfo.h
index 6eaf0c9..6cafb55 100644
--- a/llvm/lib/Target/Mips/MipsSelectionDAGInfo.h
+++ b/llvm/lib/Target/Mips/MipsSelectionDAGInfo.h
@@ -18,9 +18,11 @@
 
 namespace llvm {
 
+class MipsTargetMachine;
+
 class MipsSelectionDAGInfo : public TargetSelectionDAGInfo {
 public:
-  MipsSelectionDAGInfo();
+  explicit MipsSelectionDAGInfo(const MipsTargetMachine &TM);
   ~MipsSelectionDAGInfo();
 };