Merge fixed alloca stack adjustments into the prolog

src/IceOperand.h

Index: src/IceOperand.h
diff --git a/src/IceOperand.h b/src/IceOperand.h
index 9d9f4972329f3db58599ad9e328c5235cb2099fb..0cde5b2d6b27835cdc5b1339c58ac4806cf22a5f 100644
--- a/src/IceOperand.h
+++ b/src/IceOperand.h
@@ -290,7 +290,7 @@ public:
   bool getSuppressMangling() const { return SuppressMangling; }
   using Constant::emit;
   void emit(TargetLowering *Target) const final;
-  void emitWithoutPrefix(TargetLowering *Target) const;
+  void emitWithoutPrefix(const TargetLowering *Target) const;
   using Constant::dump;
   void dump(const Cfg *Func, Ostream &Str) const override;