https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95205
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- read the full message, you need to copy gcc/tm.texi to $src/gcc/doc/
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95205
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- read the full message, you need to copy gcc/tm.texi to $src/gcc/doc/