[mlvm] fix and enable throw/catch adapters in MHTransformationGen

MLVM method handle graph generator has code for testing throw and catch method handle adapters (java.lang.invoke.MethodHandles.throwException() and MethodHandles.catchException()). This code had been disabled because of bugs in it.

It would be good to fix and enable this code.

To find the catch/throw testing code, look for usages of USE_THROW_CATCH constant in src/vm/mlvm/meth/share/MHTransformationGen.java.