* lib/gnat.exp (gnat_init): Remove GNAT_UNDER_TEST_ORIG.
	(gnat_target_compile): Likewise.
	Reinitialize GNAT_UNDER_TEST if target changes.
	Set ADA_INCLUDE_PATH, ADA_OBJECTS_PATH in environment.
	(local_find_gnatmake): Pass full --GCC to gnatlink.
	Remove --LINK.

From-SVN: r157240