[code-reflection] RFR: Code model attribute hard-coded [v2]

[Adam Sotona]

> This is yet another experimental serialization of code model into a custom method attribute.
> It is based on #282 with all the ops tagged and hard-coded and a bit better utilization of constant pool.
> 
> Proportional size of the custom attributes vs. text-encoded fields is 21% (16% of the CP entries).

Adam Sotona has updated the pull request incrementally with one additional commit since the last revision:

  code cleanup

-------------

Changes:
  - all: https://git.openjdk.org/babylon/pull/290/files
  - new: https://git.openjdk.org/babylon/pull/290/files/7a94d8db..15f241e3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=290&range=01
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=290&range=00-01

  Stats: 5 lines in 1 file changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/babylon/pull/290.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/290/head:pull/290

PR: https://git.openjdk.org/babylon/pull/290