Irregexp-ia32: Fixes register misuse in frame-align code that fails on Mac.

src/regexp-macro-assembler-ia32.h

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 201 matching lines @@
 
   // Pops a value from the backtrack stack. Reads the word at the stack pointer
   // (ecx) and increments it by a word size.
   inline void Pop(Register target);
 
   // Before calling a C-function from generated code, align arguments on stack.
   // After aligning the frame, arguments must be stored in esp[0], esp[4],
   // etc., not pushed. The argument count assumes all arguments are word sized.
   // Some compilers/platforms require the stack to be aligned when calling
   // C++ code.
-  inline void FrameAlign(int num_arguments);
+  // Needs a scratch register to do some arithmetic. This register will be
+  // trashed.
+  inline void FrameAlign(int num_arguments, Register scratch);
 
   // Calls a C function and cleans up the space for arguments allocated
   // by FrameAlign. The called function is not allowed to trigger a garbage
   // collection, since that might move the code and invalidate the return
   // address (unless this is somehow accounted for).
   inline void CallCFunction(Address function_address, int num_arguments);
 
   MacroAssembler* masm_;
 
   // Constant buffer provider. Allocates external storage for storing
@@ skipping 19 matching lines @@
   Label check_preempt_label_;
   Label stack_overflow_label_;
 
   // Handle used to represent the generated code object itself.
   Handle<Object> self_;
 };
 
 }}  // namespace v8::internal
 
 #endif /* REGEXP_MACRO_ASSEMBLER_IA32_H_ */