[SHT_LLVM_FUNC_ADDR_MAP] Introduce function address map section and emit dynamic instruction count

[wlei-llvm]

No description provided.

[rlavaee]

Appreciate you doing this. I think we should now split this into at least three smaller PRs:

1. ObjectYaml changes which allow testing.
2. ELF support for encoding and decoding.
3. CodeGen changes for emitting the section.

[wlei-llvm]

Appreciate you doing this. I think we should now split this into at least three smaller PRs:

1. ObjectYaml changes which allow testing.
2. ELF support for encoding and decoding.
3. CodeGen changes for emitting the section.

I split this into the following small PRs according to the suggestion! Thank you!

#124332 [SHT_LLVM_FUNC_MAP][ObjectYaml]Introduce function address map section and emit dynamic instruction count(ObjectYaml part)
#124333 [SHT_LLVM_FUNC_MAP][llvm-readobj]Introduce function address map section and emit dynamic instruction count(readobj part)
#124334 [SHT_LLVM_FUNC_MAP][CodeGen]Introduce function address map section and emit dynamic instruction count(CodeGen part)