interpreter: Add experimental lambda opcodes for invoke/create-lambda

These opcodes are not yet fully specified, and *will* change before they become shippable.
Do not write production code against experimental opcodes.

--

Implement partial interpreter support for new dex instructions invoke/create-lambda, and a
new opcode format 25x.

* Does not verify, in fact verification will soft fail when we see those opcodes.
* Compilers will punt to interpreter since they don't support new opcodes.
* As there is no way to capture/liberate variables yet, the "closure" is just
  an ArtMethod for the time being.

All new opcodes are disabled by default, use runtime option -Xexperimental-lambdas to enable them.

For example:
  dalvikvm ... -Xexperimental-lambdas ...
  dex2oat --runtime-arg -Xexperimental-lambdas ...

Change-Id: I6c996ca32a9b54ec45ec21d7a959b84dfb8a24eb