Qt 5 vs Qt 6 revisited plus 'make depend' update

Rename the recently added timestamp file used to throw away old qt
'moc' files from moc.qt5 or moc.qt6 to Qt5.h-t or Qt6.h-t and use
that to also throw away old qt_*.o when switching from Qt 5 to Qt 6
or vice versa.  Temporarily the old names remain in Makefile.src's
'clean' target and in src/.gitignore but those will be removed soon.

Update 'make depend' to add the timestamp file to qt_*.o dependencies.
Have it generate rules to build qt_*.moc from ../win/Qt/qt_*.h instead
of using a template rule in hints/include/compiler.370.  So building
the Qt interface doesn't require use of that hints file anymore and
someone reading Makefile.src won't have to know about it, but using
those hints will make their life easier.

Simplify the Qt timestamp handling portion of compiler.370.  Only one
extra rule gets added when creating src/Makefile.

src/Makefile generated from sys/unix/Makefile.src that's been rebuilt
with 'make depend' got broken by uncommenting '#include "amiconf.h"'
in global.h.  That file isn't in include/ but every object file now
depended on it and make didn't know what to do about that.  Have
depend.awk treat it as a special case so that no object files depend
on it.  That means that actually modifying it won't trigger a rebuild;
anyone fiddling with that will have to always do 'make clean' or
'touch config.h-t' after changing it.  The alternative is to move it
from outdated/include/ back to include/.

In depend.awk, recent gawk complained that "\." wasn't a defined
escape sequence in regular expressions so it would be treated as ".".
That's exactly what is intended but change it to "[.]" to avoid the
warning.  Similarly for one instance each of "\#" and '\"'.  I also
tried changing "\/" to "[/]" even though that is a defined sequence
and doesn't trigger any warning.  gawk accepted it but the awk that
comes with OSX choked on it so I changed it back to "\/".

sys/unix/hints/include/compiler.370

@@ -118,21 +118,18 @@ ifdef MAKEFILE_SRC
 ifdef WANT_WIN_QT
 # when switching from Qt5 to Qt6 or vice versa, any old .moc files will be
 # incompatible; get rid of them in case user hasn't run 'make spotless';
-# moc.qt5 and moc.qt6 are empty timestamp files and at most one should exist
+# object files are incompatable with Qt library, so get rid of them too;
+# Qt*.h-t are empty timestamp files and at most one should exist
+QTany_H = Qt*.h-t
 ifdef WANT_WIN_QT6
 # Qt 6 builds and runs (with a couple of warnings) but needs more testing
-MOCSTAMP=moc.qt6
+QTn_H = Qt6.h-t
 else
 # Qt 5 is currently the default version for nethack 3.7.x's Qt interface
-MOCSTAMP=moc.qt5
+QTn_H = Qt5.h-t
 endif
-# rule to build src/qt_foo.moc from win/Qt/qt_foo.h
-%.moc : ../win/Qt/%.h $(MOCSTAMP)
-	$(MOCPATH) -o $@ $<
-moc.qt5::
-	@if test ! -f moc.qt5; then ( rm -f *.moc moc.qt6; touch $@ ); fi;
-moc.qt6::
-	@if test ! -f moc.qt6; then ( rm -f *.moc moc.qt5; touch $@ ); fi;
+$(QTn_H) ::
+	@if test ! -f $@; then ( rm -f $(QTany_H) *.moc qt_*.o; touch $@ ); fi;
 endif #WANT_WIN_QT
 endif #MAKFILE_SRC