adaint.c: Test for __linux__ instead of linux and __sun__ instead of sun.

adaint.c: Test for __linux__ instead of linux and __sun__ instead of sun.

	* adaint.c: Test for __linux__ instead of linux and __sun__ instead
	of sun.  Add missing leading underscore to AIX.  Remove #elif 0.
	* adaint.h: Likewise.
	* cio.c: Likewise.
	* cstreams.c: Likewise.
	* env.c: Likewise.
	* gsocket.h: Likewise.
	* init.c: Likewise.  Test for __i386__ instead of i386.
	* link.c: Likewise.
	* s-oscons-tmplt.c: Likewise.
	* sysdep.c: Likewise.
	* terminals.c: Likewise.  Use BSD symbol instead of FREEBSD.
	* tracebak.c: Likewise.  Test for __sparc__ instead of sparc.

From-SVN: r223890