Clean up the x86 assembler API.

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
diff --git a/src/ia32/macro-assembler-ia32.h b/src/ia32/macro-assembler-ia32.h
index ff9f747ebadcc433d4e3cb72dc8d8d7308cb8d84..a1b42c280cecf9f69acace7795d51589e5e05161 100644
--- a/src/ia32/macro-assembler-ia32.h
+++ b/src/ia32/macro-assembler-ia32.h
@@ -246,6 +246,15 @@ class MacroAssembler: public Assembler {
   void SetCallKind(Register dst, CallKind kind);
 
   // Invoke the JavaScript function code by either calling or jumping.
+  void InvokeCode(Register code,
+                  const ParameterCount& expected,
+                  const ParameterCount& actual,
+                  InvokeFlag flag,
+                  const CallWrapper& call_wrapper,
+                  CallKind call_kind) {
+    InvokeCode(Operand(code), expected, actual, flag, call_wrapper, call_kind);
+  }
+
   void InvokeCode(const Operand& code,
                   const ParameterCount& expected,
                   const ParameterCount& actual,
@@ -387,7 +396,7 @@ class MacroAssembler: public Assembler {
   void SmiTag(Register reg) {
     STATIC_ASSERT(kSmiTag == 0);
     STATIC_ASSERT(kSmiTagSize == 1);
-    add(reg, Operand(reg));
+    add(reg, reg);
   }
   void SmiUntag(Register reg) {
     sar(reg, kSmiTagSize);