Re-enable OSR.

1) Fix flaky test by doing explicit ProfilingInfo allocation,
   and OSR compilation instead of relying on the system. Also
   make sure the method $noinline$inlineCache always starts
   with the interpreter, as otherwise we would infinite loop.

2) Ensure the thread doing the OSR cannot be suspended once it
   holds an OSR method, as otherwise the jit code cache could
   delete the method before the thread had a chance to jump to it.

Change-Id: Ic0dee181a7b23260419a94a7d7405f150433d31a