Fix up some JDWP stuff

Fix up some JDWP stuff

Notably:
- Claim to know about synthetic attributes (canGetSyntheticAttribute).
  Set an appropriate flag in the access flags of fields and methods.
  (Makes no difference that I can see in Eclipse.)
- Stop making copies of descriptor strings.  That ceased to be necessary
  after they were normalized in DEX (pre-1.0).
- Correct object type determination, especially w.r.t. the specially-
  tagged types (strings, threads, classloaders, etc).
- Handle a FIELD_ONLY mod (not tested).
- Added a bit of debugging stuff.

Change-Id: I5651b5b76d904a9edbd051e039423795faaa1650