PATCH: Fix bit-rotted --enable-maintainer-mode (bootstrap/20437)

[Tom Tromey]

>>>>> "Laurynas" == Laurynas Biveinis <laurynas.biveinis@gmail.com> writes:

Laurynas> This patch fixes autotools invocation for fixincludes if srcdir !=
Laurynas> objdir and adds missing gcc/Makefile.in dependency. I'm asking for
Laurynas> approval, but I wonder if such patches are considered obvious?

I usually interpret "obvious" as really obvious things like typos,
but opinions vary here.

This patch looks reasonable to me.  I can't approve it though.

Tom