6939203: JSR 292 needs method handle constants
Summary: Add new CP types CONSTANT_MethodHandle, CONSTANT_MethodType to verifier; put in runtime support upcall.
Reviewed-by: twisti
6939196: method handle signatures off the boot class path get linkage errors
Summary: Remove workaround from MethodHandleImpl lookup code; add JUnit regression test to MethodHandlesTest.
Reviewed-by: twisti