Fix two compile time const issues

runtime/vm/ast.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 
@@ skipping 120 matching lines @@
     case Token::kLTE:
     case Token::kGTE:
       if (left_val->IsNumber() && right_val->IsNumber()) {
         return &Bool::ZoneHandle(Bool::False());
       }
       return NULL;
     case Token::kEQ:
     case Token::kNE:
     case Token::kEQ_STRICT:
     case Token::kNE_STRICT:
-      if ((left_val->IsNumber() && right_val->IsNumber()) ||
-          (left_val->IsString() && right_val->IsString()) ||
-          (left_val->IsBool()   && right_val->IsBool())) {
+      // The comparison is a compile time const if both operands are either a
+      // number, string, or boolean value (but not necessarily the same type).
+      if ((left_val->IsNumber() ||
+          left_val->IsString() ||
+          left_val->IsBool()) &&
+          (right_val->IsNumber() ||
+          right_val->IsString() ||
+          right_val->IsBool())) {
         return &Bool::ZoneHandle(Bool::False());
       }
       return NULL;
     default:
       return NULL;
   }
   return NULL;
 }
 
 
@@ skipping 48 matching lines @@
   const Instance* right_val = this->right()->EvalConstExpr();
   if (right_val == NULL) {
     return NULL;
   }
   switch (kind_) {
     case Token::kADD:
     case Token::kSUB:
     case Token::kMUL:
     case Token::kDIV:
     case Token::kMOD:
+    case Token::kTRUNCDIV:
       if (left_val->IsInteger()) {
         if (right_val->IsInteger()) {
           return left_val;
         } else if (right_val->IsNumber()) {
           return right_val;
         }
       } else if (left_val->IsNumber() &&
                  right_val->IsNumber()) {
         return left_val;
       }
       return NULL;
-    case Token::kTRUNCDIV:
     case Token::kBIT_OR:
     case Token::kBIT_XOR:
     case Token::kBIT_AND:
     case Token::kSHL:
     case Token::kSHR:
       if (left_val->IsInteger() &&
           right_val->IsInteger()) {
         return right_val;
       }
       return NULL;
@@ skipping 198 matching lines @@
     // the Error object directly to the parser.  This will involve
     // replumbing all of the EvalConstExpr methods.
     return NULL;
   }
   Instance& field_value = Instance::ZoneHandle();
   field_value ^= result.raw();
   return &field_value;
 }
 
 }  // namespace dart