6939196: method handle signatures off the boot class path get linkage errors
Summary: Adjust MethodType lookup logic to search off the BCP, but not to cache those results
Reviewed-by: twisti
6939134: JSR 292 adjustments to method handle invocation
Summary: split MethodHandle.invoke into invokeExact and invokeGeneric; also clean up JVM-to-Java interfaces
Reviewed-by: twisti