ARM improvements to constant div, mod and mul....

src/arm/codegen-arm.h

Index: src/arm/codegen-arm.h
===================================================================
--- src/arm/codegen-arm.h	(revision 2339)
+++ src/arm/codegen-arm.h	(working copy)
@@ -186,6 +186,8 @@
   bool in_spilled_code() const { return in_spilled_code_; }
   void set_in_spilled_code(bool flag) { in_spilled_code_ = flag; }
 
+  static const int kUnknownIntValue = -1;
+
  private:
   // Construction/Destruction
   CodeGenerator(int buffer_size, Handle<Script> script, bool is_eval);
@@ -291,7 +293,9 @@
 
   void ToBoolean(JumpTarget* true_target, JumpTarget* false_target);
 
-  void GenericBinaryOperation(Token::Value op, OverwriteMode overwrite_mode);
+  void GenericBinaryOperation(Token::Value op,
+                              OverwriteMode overwrite_mode,
+                              int known_rhs = kUnknownIntValue);
   void Comparison(Condition cc,
                   Expression* left,
                   Expression* right,