[PATCH 2/2] sparc: Run SUBTARGET_INIT_BUILTINS if it exists

[coypu@sdf.org]

I hope that writing the detailed commit message will encourage someone
with better knowledge of GCC internals to point out a better place for
this logic. I can follow through with any suggestions :)

On Sat, Feb 13, 2021 at 12:20:30PM +0000, Maya Rashish wrote:
> Some subtargets don't provide the canonical function names as
> the symbol name in C libraries, and libcalls will only work if
> the builtins are patched to emit the correct library name.
> 
> For example, on NetBSD, cabsl has the symbol name __c99_cabsl,
> and the patching is done via netbsd_patch_builtin.
> 
> With this change, libgfortran.so is correctly built with a
> reference to __c99_cabsl, instead of "cabsl" which is not defined.