This completes (at least for now) the project of getting rid of ad-hoc
linkages among the src/bin/ subdirectories. Everything they share is now
in src/fe_utils/ and is included from a static library at link time.
A side benefit is that we can restore the FLEX_NO_BACKUP check for
psqlscanslash.l. We might need to think of another way to do that check
if we ever need to build two lexers with that property in the same source
directory, but there's no foreseeable reason to need that.
Per discussion, we want to create a static library and put the stuff into
it that until now has been shared across src/bin/ directories by ad-hoc
methods like symlinking a source file. This commit creates the library and
populates it with a couple of files that contain the widely-useful portions
of pg_dump's dumputils.c file. dumputils.c survives, because it has some
stuff that didn't seem appropriate for fe_utils, but it's significantly
smaller and is no longer referenced from any other directory.
Follow-on patches will move more stuff into fe_utils.
The Mkvcbuild.pm hacking here is just a best guess; we'll see how the
buildfarm likes it.
Tom Lane