Add a RegisterMaskSDNode class.

This SelectionDAG node will be attached to call nodes by LowerCall(),
and eventually becomes a MO_RegisterMask MachineOperand on the
MachineInstr representing the call instruction.

LowerCall() will attach a register mask that depends on the calling
convention.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148436 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index fbf6d77..bcccefd 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -351,6 +351,8 @@
     MI->addOperand(MachineOperand::CreateFPImm(CFP));
   } else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
     MI->addOperand(MachineOperand::CreateReg(R->getReg(), false));
+  } else if (RegisterMaskSDNode *RM = dyn_cast<RegisterMaskSDNode>(Op)) {
+    MI->addOperand(MachineOperand::CreateRegMask(RM->getRegMask()));
   } else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) {
     MI->addOperand(MachineOperand::CreateGA(TGA->getGlobal(), TGA->getOffset(),
                                             TGA->getTargetFlags()));