Fix a bug in ia32 shift left , implemented more inlined binary operations in x64.

runtime/vm/token.h

Index: runtime/vm/token.h
===================================================================
--- runtime/vm/token.h	(revision 8116)
+++ runtime/vm/token.h	(working copy)
@@ -178,6 +178,8 @@
   KW(kWHILE, "while", 0, kKeyword) /* == kLastKeyword */
 
 
+class String;
+
 class Token {
  public:
 #define T(t, s, p, a) t,
@@ -266,6 +268,9 @@
             (tok == Token::kDOUBLE));
   }
 
+  // Returns kILLEGAL if 'name' does not match a BinaryOp.
+  static Token::Kind GetBinaryOp(const String& name);
+
  private:
   static const char* name_[];
   static const char* tok_str_[];