Sink getDwarfRegNum, getLLVMRegNum, getSEHRegNum from TargetRegisterInfo down
to MCRegisterInfo. Also initialize the mapping at construction time.

This patch eliminate TargetRegisterInfo from TargetAsmInfo. It's another step
towards fixing the layering violation.

llvm-svn: 135424
diff --git a/llvm/lib/Target/PTX/MCTargetDesc/PTXMCTargetDesc.cpp b/llvm/lib/Target/PTX/MCTargetDesc/PTXMCTargetDesc.cpp
index 23f70bd..065e698 100644
--- a/llvm/lib/Target/PTX/MCTargetDesc/PTXMCTargetDesc.cpp
+++ b/llvm/lib/Target/PTX/MCTargetDesc/PTXMCTargetDesc.cpp
@@ -40,6 +40,18 @@
   TargetRegistry::RegisterMCInstrInfo(ThePTX64Target, createPTXMCInstrInfo);
 }
 
+static MCRegisterInfo *createPTXMCRegisterInfo(StringRef TT) {
+  MCRegisterInfo *X = new MCRegisterInfo();
+  // PTX does not have a return address register.
+  InitPTXMCRegisterInfo(X, 0);
+  return X;
+}
+
+extern "C" void LLVMInitializePTXMCRegisterInfo() {
+  TargetRegistry::RegisterMCRegInfo(ThePTX32Target, createPTXMCRegisterInfo);
+  TargetRegistry::RegisterMCRegInfo(ThePTX64Target, createPTXMCRegisterInfo);
+}
+
 static MCSubtargetInfo *createPTXMCSubtargetInfo(StringRef TT, StringRef CPU,
                                                  StringRef FS) {
   MCSubtargetInfo *X = new MCSubtargetInfo();