On PA-RISC, the _GLOBAL_OFFSET_TABLE_ symbol is always exposed. See https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=bfd/elf32-hppa.c;h=2e653083ce05a77b3e33c056e2f9a51b327c2b22#l1001 https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=blob;f=sysdeps/hppa/dl-machine.h;h=9e98366ea3b09612d54a3e956d5c35c1bdc86560#l80
These use the symbol-check.py script from mesa, and should help to ensure that glvnd doesn't start exposing/hiding new symbols. It's also useful to double check that meson and autotools are doing the same thing.