[Bug driver/112759] [13/14 regression] mips -march=native detection broken with gcc 13+ since r13-3178-g66c48be23e0fa5

[syq at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112759

--- Comment #5 from YunQiang Su <syq at gcc dot gnu.org> ---
It's my fault.
I misunderstanding `reconcat`:

if `optr` is NULL, it cannot work as the `s1` at the sametime.
If so, the return string will be empty.

So, let's define and initial ret like this:

char *ret = concat(" "); 

Any idea?