@GOTPCREL_NORELAX relocation notation

[Matt Morehouse]

Hi folks,

We have an LLVM patch [1] to introduce the new relocation
type @GOTPCREL_NORELAX in assembly.  It is like @GOTPCREL but guarantees
that the assembler emits an R_X86_64_GOTPCREL relocation instead of the
relaxable R_X86_64[_REX]_GOTPCRELX variants.

Are you interested in adopting a similar feature for GNU as?  If so, it may
be a good idea to have some consensus on the notation -- Is
@GOTPCREL_NORELAX good, or should we do something else?

Thanks,
Matt Morehouse

[1] https://reviews.llvm.org/D113220