[asan][test] Don't XFAIL Posix/no_asan_gen_globals.c on Solaris

One ASan test currently `XPASS`es on Solaris:

  AddressSanitizer-i386-sunos :: TestCases/Posix/no_asan_gen_globals.c

It was originally `XFAIL`ed in D88218 <https://reviews.llvm.org/D88218>
because Solaris `ld`, unlike GNU `ld`, doesn't strip local labels.  Since
then, the integrated assembler has stopped emitting those local labels, so
the difference becomes moot and the `XFAIL` can go.

Tested on `amd64-pc-solaris2.11` and `x86_64-pc-linux-gnu`.

Differential Revision: https://reviews.llvm.org/D97932