[code-reflection] RFR: Bytecode round 9 [v2]

[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 with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains ten additional commits since the last revision:

 - LocalTypeMapper performs iterative correction of int stack map frame entries to support byte, boolean, short and char types
 - Merge branch 'code-reflection' into bytecode-round-9
 - removed obsolete BytecodeGenerator::conversion
 - removed debug output
 - BytecodeLift fixes of code branching with deep stack and unitialized frame objects
 - fixed LocalsTypeMapper to track uninitialized types
 - fixed LocalsTypeMapper and lambdas lifting
 - fixed generating of non-String concats
 - lifting concats

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

Changes:
  - all: https://git.openjdk.org/babylon/pull/192/files
  - new: https://git.openjdk.org/babylon/pull/192/files/44faf012..edf96390

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=192&range=01
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=192&range=00-01

  Stats: 25417 lines in 141 files changed: 24349 ins; 873 del; 195 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