Pixman configure.ac has AC_SUBST(AC_MAJOR)

[David Sharp]

I don't think AC_MAJOR is a defined Autoconf or Automake macro. Google
reveals no useful information, and I can't find any reference to it in
any recent version of the Auto(make|conf) info pages.

This was introduced in 7b3c9cef49cdedef03112054925005fa21120bd5
(Change the library name to pixman-1) by Søren Sandmann Pedersen
<sandmann at redhat.com>.

Removing the line allows Pixman to build. I wonder if the line was
supposed to read:

AC_SUBST(PIXMAN_MAJOR)

as it immediately follows

PIXMAN_MAJOR=pixman_major

Neither variable/substitution is referenced anywhere else in the pixman tree.

Thanks,
d#