[code-reflection] RFR: OpBuilder optimizations - part 1. [v5]

[Adam Sotona]

> This PR include following changes:
> 
> - op-building methods isolated from the original code and moved to a synthetic inner class
> - fixed boxing in `OpBuilder`
> - op-building methods are generated by `BytecodeGenerator` and support wide range of ops
> - `CodeModelTranslator` is deleted
> - synthetic op-building method overrides significantly reduce overhead (by 60% on `TestBytecode`)
> 
> Remaining tasks:
> 
> - implement part 2. type-building helper method(s) to reduce the overhead even more
> - refactor `OpBuilder` to build `ModuleOp` instead of individual `FuncOp`s (and re-enable `TestCodeBuilder`)
> - cleanup `BytecodeGenerator` API

Adam Sotona has updated the pull request incrementally with two additional commits since the last revision:

 - Op reverted to the original
   
 - builder methods delegating to the synth. inner class

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

Changes:
  - all: https://git.openjdk.org/babylon/pull/679/files
  - new: https://git.openjdk.org/babylon/pull/679/files/e0499280..768c6028

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=679&range=04
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=679&range=03-04

  Stats: 25 lines in 2 files changed: 21 ins; 3 del; 1 mod
  Patch: https://git.openjdk.org/babylon/pull/679.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/679/head:pull/679

PR: https://git.openjdk.org/babylon/pull/679