With cpp and gcc 2.96-69 and 2.96-70, the compiler-generated
dependencies (-Wp,-MD,file) don't list files included via
-include.  (In gcc 2.91, such files were listed.)

I'll attach a testcase that compiles using the command:

gcc -o incltest.o -include incltest.h -Wp,-MD,incltest.d incltest.c

This generates incltest.d containing:

incltest.o: incltest.c

If I set CC=kgcc (which is gcc 2.91), it generates incltest.d as:

incltest.o: incltest.c incltest.h

I noticed this because making configure.in changes to Mozilla that
modified config-deps.h (a file used instead of -D...) wasn't causing
a full rebuild anymore.  While this is actually sometimes useful, I
still think it's a bug.

I'll attach a testcase (in tar.gz) of the Makefile and test files
mentioned above.