gdbarch_static_transform_name is completely Solaris-specific or rather
specific to the Studio compilers. Studio cc has deprecated Stabs support
in the 12.4 release back in 2015, GCC has defaulted to DWARF-2 on Solaris
7+ since 2004 and Stabs themselves are pretty much obsolete, so the whole
code can go.
Tested on sparcv9-sun-solaris2.11 and x86_64-pc-linux-gnu with
--enable-targets=all.