[code-reflection] RFR: Bytecode round 9 [v4]

[Adam Sotona]

> Bytecode round 9 contains following improvements:
> - `String` (and non-`String`) concats are lifted to `CoreOp.ConcatOp`
> - `LocalsTypeMapper` is fixed to use instruction index as a key (instead of the instruction identity)
> - `LocalsTypeMapper` newly calculates types of uninitialized stack map frame entries and provides that info to `BytecodeLift`
> - `BytecodeLift` is fixed to handle deep stacks correctly while branching + tests added
> - Oboslete `BytecodeGenerator::conversion` method is replaced by direct call of `CodeBuilder::conversion`
> - LocalTypeMapper performs iterative correction of int stack map frame entries to support byte, boolean, short and char types
> 
> `TestSmallCorpus` is not experiencing any first-lift exceptions after the above changes, however we cannot yet say that all the lifted models are correct.
> 
> Please review.
> 
> Thanks,
> Adam

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

  fixed lifting and generation of non-void returning MH used in void returning INDY calls

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

Changes:
  - all: https://git.openjdk.org/babylon/pull/192/files
  - new: https://git.openjdk.org/babylon/pull/192/files/8bc8d2fd..e2c90bec

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=192&range=03
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=192&range=02-03

  Stats: 29 lines in 3 files changed: 21 ins; 3 del; 5 mod
  Patch: https://git.openjdk.org/babylon/pull/192.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/192/head:pull/192

PR: https://git.openjdk.org/babylon/pull/192