Well, that's pretty slick! V8 seems to run this code unless I attach a debugger. JScript (which seems easier to debug) does not (which complains about constructor.prototype not being defined). If I try to attach Eclipse with this hack in I get an appcash in QTAgent32.exe:
<ProblemSignatures>
<EventType>APPCRASH</EventType>
<Parameter0>QTAgent32.exe</Parameter0>
<Parameter1>11.0.50727.1</Parameter1>
<Parameter2>5011df53</Parameter2>
<Parameter3>StackHash_08ac</Parameter3>
<Parameter4>0.0.0.0</Parameter4>
<Parameter5>00000000</Parameter5>
<Parameter6>c0000005</Parameter6>
<Parameter7>74e0cb49</Parameter7>
</ProblemSignatures>
<DynamicSignatures>
<Parameter1>6.1.7601.2.1.0.256.48</Parameter1>
<Parameter2>1033</Parameter2>
<Parameter22>08ac</Parameter22>
<Parameter23>08ac7c35000c889c52b861a824ddc684</Parameter23>
<Parameter24>2ac4</Parameter24>
<Parameter25>2ac405e344ce12df2b2c2da92f28dde5</Parameter25>
</DynamicSignatures>
Thanks, though, that does seem to do exactly what I want even if it might not be available in the future.