Avoid integer overflow when computing the size of new space in bytes.

runtime/vm/heap.cc

 // Copyright (c) 2012, 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/heap.h"
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/compiler_stats.h"
 #include "vm/flags.h"
@@ skipping 18 matching lines @@
 DEFINE_FLAG(bool, gc_at_alloc, false, "GC at every allocation.");
 DEFINE_FLAG(int, new_gen_heap_size, 32, "new gen heap size in MB,"
             "e.g: --new_gen_heap_size=64 allocates a 64MB new gen heap");
 DEFINE_FLAG(int, old_gen_heap_size, Heap::kHeapSizeInMB,
             "old gen heap size in MB,"
             "e.g: --old_gen_heap_size=1024 allocates a 1024MB old gen heap");
 DEFINE_FLAG(int, code_heap_size, Heap::kCodeHeapSizeInMB,
             "code heap size in MB,"
             "e.g: --code_heap_size=8 allocates a 8MB code heap");
 
-  Heap::Heap() : read_only_(false) {
+Heap::Heap() : read_only_(false) {
   new_space_ = new Scavenger(this,
                              (FLAG_new_gen_heap_size * MB),
                              kNewObjectAlignmentOffset);
   old_space_ = new PageSpace(this, (FLAG_old_gen_heap_size * MB));
   code_space_ = new PageSpace(this, (FLAG_code_heap_size * MB), true);
 }
 
 
 Heap::~Heap() {
   delete new_space_;
@@ skipping 341 matching lines @@
   isolate()->IncrementNoGCScopeDepth();
 }
 
 
 NoGCScope::~NoGCScope() {
   isolate()->DecrementNoGCScopeDepth();
 }
 #endif  // defined(DEBUG)
 
 }  // namespace dart