Revert Ada .cc renaming renaming.

Revert Ada .cc renaming renaming.

gcc/ada/ChangeLog:

	* Make-generated.in: Revert renaming changes.
	* Makefile.rtl: Likewise.
	* adadecode.cc: Moved to...
	* adadecode.c: ...here.
	* affinity.cc: Moved to...
	* affinity.c: ...here.
	* argv-lynxos178-raven-cert.cc: Moved to...
	* argv-lynxos178-raven-cert.c: ...here.
	* argv.cc: Moved to...
	* argv.c: ...here.
	* aux-io.cc: Moved to...
	* aux-io.c: ...here.
	* cio.cc: Moved to...
	* cio.c: ...here.
	* cstreams.cc: Moved to...
	* cstreams.c: ...here.
	* env.cc: Moved to...
	* env.c: ...here.
	* exit.cc: Moved to...
	* exit.c: ...here.
	* expect.cc: Moved to...
	* expect.c: ...here.
	* final.cc: Moved to...
	* final.c: ...here.
	* gcc-interface/Makefile.in:
	* init.cc: Moved to...
	* init.c: ...here.
	* initialize.cc: Moved to...
	* initialize.c: ...here.
	* libgnarl/thread.cc: Moved to...
	* libgnarl/thread.c: ...here.
	* link.cc: Moved to...
	* link.c: ...here.
	* locales.cc: Moved to...
	* locales.c: ...here.
	* mkdir.cc: Moved to...
	* mkdir.c: ...here.
	* raise.cc: Moved to...
	* raise.c: ...here.
	* rtfinal.cc: Moved to...
	* rtfinal.c: ...here.
	* rtinit.cc: Moved to...
	* rtinit.c: ...here.
	* s-oscons-tmplt.c (CND): Revert renaming changes.
	* seh_init.cc: Moved to...
	* seh_init.c: ...here.
	* sigtramp-armdroid.cc: Moved to...
	* sigtramp-armdroid.c: ...here.
	* sigtramp-ios.cc: Moved to...
	* sigtramp-ios.c: ...here.
	* sigtramp-qnx.cc: Moved to...
	* sigtramp-qnx.c: ...here.
	* sigtramp-vxworks.cc: Moved to...
	* sigtramp-vxworks.c: ...here.
	* socket.cc: Moved to...
	* socket.c: ...here.
	* tracebak.cc: Moved to...
	* tracebak.c: ...here.
	* version.cc: Moved to...
	* version.c: ...here.
	* vx_stack_info.cc: Moved to...
	* vx_stack_info.c: ...here.