Merge TRUNCDIV and MOD into TRUNCDIV_MOD single operation.

runtime/vm/token.h

Index: runtime/vm/token.h
===================================================================
--- runtime/vm/token.h	(revision 30236)
+++ runtime/vm/token.h	(working copy)
@@ -133,7 +133,9 @@
   TOK(kSCRIPTTAG, "#!", 0, kNoAttribute)                                       \
                                                                                \
   /* Support for optimized code */                                             \
-  TOK(kREM, "", 0, kNoAttribute)                                               \
+TOK(kREM, "", 0, kNoAttribute)                                                 \
+TOK(kTRUNCDIVMOD, "", 0, kNoAttribute)                                         \
+TOK(kTRUNCDIVREM, "", 0, kNoAttribute)                                         \
 
 // List of keywords. The list must be alphabetically ordered. The
 // keyword recognition code depends on the ordering.
@@ -257,7 +259,12 @@
 
   static const char* Str(Kind tok) {
     ASSERT(tok < kNumTokens);
-    return tok_str_[tok];
+    switch (tok) {
+      case Token::kREM: return "REM";
+      case Token::kTRUNCDIVMOD: return "TRUNCDIVMOD";
+      case Token::kTRUNCDIVREM: return "TRUNCDIVREM";
+      default: return tok_str_[tok];
+    }
   }
 
   static int Precedence(Kind tok) {