review (M) for 4926272: methodOopDesc::method_from_bcp is unsafe

[Tom Rodriguez]

4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by:

To deal transparently with breakpoint bytecodes many of the bytecode
routines may need access to the original methodOop.  Currently we are
relying on GC machinery toscan backwards to the beginning of the oop.
This doesn't always work with CMS and won't exist when we remove the
perm gen.  The fix is to require passing around the methodOop.  This
required changing these Bytecodes into StackObjs which cause a few
other syntaactic changes like converting -> to . in quite a few
places.  It created a little inconsistency with some of the other
Bytecode classes that I chose to fix.  They are all now StackObj and I
got rid of the *_at helpers and moved the verify calls into the
constructors.  I also eliminated ThisRelativeObj completely and
changed a few names.  Tested with nsk jvmti related tests.