Add support for metadata.code.branch_hint section

[Lukasdoe]

Since we're currently in the progress of upstreaming the generation of the code metadata branch hint section in llvm (PR), I also implemented support for this feature in wamr.

One important consideration for the implementation was to keep the encoding of hints generic, so that more compilation hints could be added in the future.

[Lukasdoe]

(rebased on main)

[lum1n0us]

Is there any possibility that the interpreter can also benefit from this feature?

[Lukasdoe]

Alright, the changes from the review are now committed. Thank you very much for taking the time and effort to give such a good review :)

Concerning your question about branch hints and the interpreter:
Since I only looked at the AOT part of this project, I honestly don't know and currently don't have the capacity to test this out. Maybe you know some other maintainer knows the interpreter's codebase well and could judge whether (very simple) knowledge about the probability that a branch is taken / not taken would benefit interpretation.

[Lukasdoe]

@lum1n0us when you find the time, could you please have a look over the changes after your review again? :)

[Lukasdoe]

@lum1n0us (ping)

[yamt]

@Lukasdoe can you resolve the conflicts?