Adds a flag to the standalone vm to throw an exception on 53-bit integer overflow.

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 23032)
+++ runtime/vm/object.cc	(working copy)
@@ -10398,6 +10398,12 @@
 }
 
 
+bool Integer::FitsIn53Bits() const {
+  UNIMPLEMENTED();
+  return false;
+}
+
+
 int Integer::CompareWith(const Integer& other) const {
   UNIMPLEMENTED();
   return 0;
@@ -10772,6 +10778,12 @@
 }
 
 
+bool Mint::FitsIn53Bits() const {
+  int64_t v = AsInt64Value();
+  return Utils::IsInt(53, v);
+}
+
+
 int Mint::CompareWith(const Integer& other) const {
   ASSERT(!FitsIntoSmi(*this));
   if (other.IsMint() || other.IsSmi()) {