[Bug libgcc/63684] Build failure due to "Let GDB reuse GCC's parser."

[sasha.levin at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63684

--- Comment #13 from Sasha Levin <sasha.levin at oracle dot com> ---
>From "Installing GCC: Configuration"
(https://gcc.gnu.org/install/configure.html):

"building where srcdir == objdir should still work, but doesn't get extensive
testing"