Add flag to print stack trace on illegal exception.

This would help a lot with native Javascript code.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/156373003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19251 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/flag-definitions.h

@@ -591,6 +591,8 @@ DEFINE_int(sim_stack_alignment, 8,
            "Stack alingment in bytes in simulator (4 or 8, 8 is default)")
 
 // isolate.cc
+DEFINE_bool(stack_trace_on_illegal, false,
+            "print stack trace when an illegal exception is thrown")
 DEFINE_bool(abort_on_uncaught_exception, false,
             "abort program (dump core) when an uncaught exception is thrown")
 DEFINE_bool(trace_exception, false,

src/isolate.cc

@@ -946,6 +946,7 @@ Failure* Isolate::ReThrow(MaybeObject* exception) {
 
 
 Failure* Isolate::ThrowIllegalOperation() {
+  if (FLAG_stack_trace_on_illegal) PrintStack(stdout);
   return Throw(heap_.illegal_access_string());
 }