Split ISD::LABEL into ISD::DBG_LABEL and ISD::EH_LABEL, eliminating

the need for a flavor operand, and add a new SDNode subclass,
LabelSDNode, for use with them to eliminate the need for a label id
operand.

Change instruction selection to let these label nodes through
unmodified instead of creating copies of them. Teach the MachineInstr
emitter how to emit a MachineInstr directly from an ISD label node.

This avoids the need for allocating SDNodes for the label id and
flavor value, as well as SDNodes for each of the post-isel label,
label id, and label flavor.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52943 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86CodeEmitter.cpp

@@ -490,7 +490,8 @@ void Emitter::emitInstruction(const MachineInstr &MI,
     case TargetInstrInfo::INLINEASM:
       assert(0 && "JIT does not support inline asm!\n");
       break;
-    case TargetInstrInfo::LABEL:
+    case TargetInstrInfo::DBG_LABEL:
+    case TargetInstrInfo::EH_LABEL:
       MCE.emitLabel(MI.getOperand(0).getImm());
       break;
     case TargetInstrInfo::IMPLICIT_DEF: