[PATCH 0/4] gas: Add support for LLVM addrsig and addrsig_sym.

[Fangrui Song]

On 2022-05-25, Tatsuyuki Ishi via Binutils wrote:
>This patch adds support for the relevant LLVM assembler directives,
>which is a prerequisite for GCC support of the feature.
>
>[1]: https://llvm.org/docs/Extensions.html#sht-llvm-addrsig-section-address-significance-table
>
>

I have to be fair, the design of SHT_LLVM_ADDRSIG has a major problem
that it does not work with objcopy and ld -r:
https://sourceware.org/bugzilla/show_bug.cgi?id=23817
That said, using relocations would greatly increase the size of the
section and the current uleb128 does a good job on decreasing the file
size...

If ld supports SHT_LLVM_ADDRSIG, it would probably make it easier
to assemble `clang -S` output with `as`. Currently, on many targets/Linux
distributions, `clang -S` defaults to -faddrsig which makes the output
not-assembable with `as`.