We already ignored a couple of them, but there's many more of them showing up
every now and then, especially because of some of the porting tools.
/UU
# files produced by './configure.gnu' on a Linux machine
-Makefile.old
/Makefile
/Policy.sh
/cflags
/makedepend
/makedir
/makefile
-/makefile.old
/myconfig
/opmini.c
/perlmain.c
/x2p/Makefile
/x2p/cflags
/x2p/makefile
-/x2p/makefile.old
# alternative names on OS X
/GNUmakefile
-/GNUmakefile.old
/x2p/GNUmakefile
-/x2p/GNUmakefile.old
# general build products
*.o
*.a
*.so
*.i
+*.old
# general build products (Win32)
*.def