Implement argument definition test in the vm.

runtime/vm/symbols.cc

Index: runtime/vm/symbols.cc
===================================================================
--- runtime/vm/symbols.cc	(revision 11663)
+++ runtime/vm/symbols.cc	(working copy)
@@ -28,6 +28,12 @@
 };
 
 
+const char* Symbols::Name(intptr_t symbol) {

[hausner, 2012/08/31 00:34:55]

Why is this needed (or better) than getting the raw pointers using
Symbols::Foo()?

Symbols::Name(Symbols::kFoo) versus Symbols::Foo()
 

[regis, 2012/08/31 01:36:18]

See the other comment. When we just need a char*, it is a waste to allocate a
handle.

+  ASSERT((symbol > kIllegal) && (symbol < kMaxId));
+  return names[symbol];
+}
+
+
 void Symbols::InitOnce(Isolate* isolate) {
   // Should only be run by the vm isolate.
   ASSERT(isolate == Dart::vm_isolate());