Cygwin: revert handwritten tags/ctags target

Converting to automake dropped the former, handwritten tags/ctags
target.  This leads to a couple of problems:

- For no good reason the tags file gets written to the builddir
  instead of to the srcdir where it's needed.

- `make tags' requires etags to exist, rather than checking if it
  exists and skipping it.

- Adding the extra ctags arguments to AM_CTAGSFLAGS still results
  in a shortened tags file.

(Temporary?) solution: Revert the old tags/ctags rules and silence
the automake warnings.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/Makefile.am

@@ -8,6 +8,8 @@
 
 # This makefile requires GNU make.
 
+#AUTOMAKE_OPTIONS=-Wno-override
+
 include $(top_srcdir)/Makefile.am.common
 
 COMMON_CFLAGS=-Wimplicit-fallthrough=5 -Werror -fmerge-constants -ftracer
@@ -23,6 +25,10 @@ if TARGET_X86_64
 AM_CCASFLAGS=-D_WIN64
 endif
 
+AM_CTAGSFLAGS=-R -f $(srcdir)/tags --c++-kinds=+p --fields=+iaS --extra=+q \
+	--regex-C++='/EXPORT_ALIAS *\([a-zA-Z0-9_]*, *([a-zA-Z0-9_]*)\)/\1/' \
+	--regex-C++='/__ASMNAME *\("([a-zA-Z0-9_]+)"\)/\1/'
+
 target_builddir=@target_builddir@
 newlib_build=$(target_builddir)/newlib
 
@@ -769,3 +775,12 @@ uninstall-headers:
 
 uninstall-ldif:
 	rm -f $(DESTDIR)$(datarootdir)/cygwin/cygwin.ldif
+
+#ctags: CTAGS
+#tags:  CTAGS
+#CTAGS:
+#	-cd $(srcdir) && \
+#	ctags -R --c++-kinds=+p --fields=+iaS --extra=+q \
+#	--regex-C++='/EXPORT_ALIAS *\([a-zA-Z0-9_]*, *([a-zA-Z0-9_]*)\)/\1/' \
+#	--regex-C++='/__ASMNAME *\("([a-zA-Z0-9_]+)"\)/\1/' \
+#	.