[stackmaps] More extraction of common code [NFCI]

General cleanup before starting to work on the part I want to actually change.

llvm-svn: 279586
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 03c8b1d..4a0d433 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -979,8 +979,7 @@
   PatchPointOpers opers(&MI);
   unsigned ScratchIdx = opers.getNextScratchIdx();
   unsigned EncodedBytes = 0;
-  const MachineOperand &CalleeMO =
-    opers.getMetaOper(PatchPointOpers::TargetPos);
+  const MachineOperand &CalleeMO = opers.getCallTarget();
 
   // Check for null target. If target is non-null (i.e. is non-zero or is
   // symbolic) then emit a call.
@@ -1016,7 +1015,7 @@
   }
 
   // Emit padding.
-  unsigned NumBytes = opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
+  unsigned NumBytes = opers.getNumPatchBytes();
   assert(NumBytes >= EncodedBytes &&
          "Patchpoint can't request size less than the length of a call.");