Have LowerOperandForConstraint handle multiple character constraints.

Part of rdar://9119939


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132510 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 64a57a1..986b4e7 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -328,7 +328,7 @@
     /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
     /// vector.  If it is invalid, don't add anything to Ops.
     virtual void LowerAsmOperandForConstraint(SDValue Op,
-                                              char ConstraintLetter,
+                                              std::string &Constraint,
                                               std::vector<SDValue> &Ops,
                                               SelectionDAG &DAG) const;