[code-reflection] RFR: BytecodeGenerator, BytecodeLift and TestBytecode improvements

[Adam Sotona]

On Fri, 22 Mar 2024 14:06:43 GMT, Adam Sotona <asotona at openjdk.org> wrote:

> BytecodeGenerator, BytecodeLift and TestBytecode improvements

This PR represents several rounds of improvements, refactoring and re-shaking of the bytecode generating and lifting code.
For `BytecodeLift` I've improved locals calculation, which allowed to return to a single-pass top-down analysis (with help of stack maps).
`BytecodeGenerator` refactoring is mostly preparation for follow up improvements. 
Both are still work in progress, however improved `TestSmallCorpus` shows stats with significant improvements.
Beside the corpus-based tests I've implemented generic and parametrized `TestBytecode`, mainly to move forward in individual generator/lift cases. Many individual test cases have been merged into `TestBytecode`.
The PR also includes patch to `Interpreter` to convert int return values to the exact function return type (byte, boolean,...). I'm not sure it is the right fix on the right place, however it at least allows `TestBytecode` to cover more types.

Please review and let me know your comments.
I would like to sync with code-reflection branch before further work.

Thank you,
Adam

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PR Comment: https://git.openjdk.org/babylon/pull/44#issuecomment-2022823396