IllegalStateOperation when interpreting complicated things

[gbrail]

I've been working on a set of performance tests based on the JetStream2 benchmarks that are more comprehensive and repeatable than what we have now. A few of the tests fail with the IllegalStateException below.

This was introduced by the big refactoring to introduce JSFunction and friends:

8e69a72

Here's the stack trace:

java.lang.IllegalStateException: FAILED ASSERTION
at org.mozilla.javascript.Kit.codeBug(Kit.java:352)
at org.mozilla.javascript.Interpreter.interpret(Interpreter.java:1437)
at org.mozilla.javascript.InterpreterData.execute(InterpreterData.java:104)
at org.mozilla.javascript.JSFunction.construct(JSFunction.java:155)
at org.brail.rhinobenchmarks.BenchmarkRunner.makeRunner(BenchmarkRunner.java:83)
at org.brail.rhinobenchmarks.BenchmarkRunner.load(BenchmarkRunner.java:51)
at org.brail.rhinobenchmarks.BenchmarkDriver.loadFile(BenchmarkDriver.java:25)
at org.brail.rhinobenchmarks.StandardBenchmarks.load(StandardBenchmarks.java:32)
at org.brail.rhinobenchmarks.Main.call(Main.java:61)
at org.brail.rhinobenchmarks.Main.call(Main.java:11)
at picocli.CommandLine.executeUserObject(CommandLine.java:2031)
at picocli.CommandLine.access$1500(CommandLine.java:148)
at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2469)
at picocli.CommandLine$RunLast.handle(CommandLine.java:2461)
at picocli.CommandLine$RunLast.handle(CommandLine.java:2423)
at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2277)
at picocli.CommandLine$RunLast.execute(CommandLine.java:2425)
at picocli.CommandLine.execute(CommandLine.java:2174)
at org.brail.rhinobenchmarks.Main.main(Main.java:101)

I'm not sure where to start with this but @aardvark179 if you have any ideas we could fix a regression that could potentially affect other things.

FWIW, the "pdfjs" and "regexp" benchmarks from the Octane test suite, and I can supply code to running them if useful.