Missing dependencies in lib-src/Makefile.in

[Eli Zaretskii <eliz@gnu.org>]

Since lib-src/Makefile.in doesn't use the automatic dependencies, all
the prerequisite header files should be spelled out explicitly, I
think, or else we will have subtle bugs.  But I don't see the required
dependencies in some cases.

Specifically, many sources include standard headers that are replaced
by gnulib in ../lib.  However, there are no prerequisite ../lib/*.h
files in lib-src/Makefile.in, with a single exception of min-max.h for
pop.o (ebrowse.c also includes min-max.h, but does not have it as a
prerequisite).

In most cases, we should probably be safe, because all the executables
are produced by compiling their *.c files, and have ../lib/libgnu.a as
their prerequisite.  So any change in lib is likely to trigger
recompilation because libgnu.a will be rebuilt.

But there are exceptions: pop.o and regex.o.  AFAICS, they will not be
recompiled if some of the headers in lib/ are modified, because none
of their prerequisites depend directly or indirectly on gnulib
headers.

Am I missing something?  If not, should this be fixed?