re PR ada/88429 (libada build fails with --disable-shared)

libada/
	PR ada/88429
	* configure.ac (default_gnatlib_target): Set to gnatlib instead of
	gnatlib-plain if --disable-shared.
	* configure: Regenerate.
	* Makefile.in (all): Replace gnatlib prerequisite with libada.
	(ADA_RTS_SUBDIR): Delete.
	(libada): New target, renamed from...
	(gnatlib): ...this.  Merge with other library targets.
	(gnatlib-plain): Delete.
	(install-gnatlib): Rename to...
	(install-libada): ...this.
	(install): Replace install-gnatlib prerequisite with install-libada.
gcc/ada/
	PR ada/88429
	* gcc-interface/Makefile.in (./stamp-gnatlib1-$(RTSDIR)): Also pass
	MULTISUBDIR to sub-make and add quotes around $(THREAD_KIND).
	(gnatlib-shared-dual): Also pass PICFLAG_FOR_TARGET to sub-make.
	(gnatlib-sjlj): Also pass MULTISUBDIR to sub-make, but do not pass
	PICFLAG_FOR_TARGET.
	(gnatlib-zcx): Likewise.

From-SVN: r267034