xsrc mesalib build problem

[Patrick Welche <prlw1%welche.eu@localhost>]

Building xsrc on -current/amd64 with 

HAVE_MESA_VER=21
HAVE_GCC=12

fails for me with

/usr/xsrc/external/mit/MesaLib/dist/src/amd/common/ac_rtld.c:658:20: error: 'STN_UNDEF' undeclared (first use in this function); did you mean 'SHN_UNDEF'?
        658 |       if (r_sym == STN_UNDEF) {
            |                    ^~~~~~~~~
            |                    SHN_UNDEF
/usr/xsrc/external/mit/MesaLib/dist/src/amd/common/ac_rtld.c:658:20: note: each undeclared identifier is reported only once for each function it appears in 

Non standard build options I know, but it had worked, and I had a complete
build on 27 March...

STN_UNDEF / SHN_UNDEF appear to be from LLVM? (and this bit of build I think
is gallium == llvmpipe?)


Cheers,

Patrick