* doc/extend.texi (flatten attribute): Remove note about unit-at-a-time
	* doc/invoke.texi (--combine): Likewise.
	(-finline-functions-called-once): Update levels when enabled.
	(-funit-at-a-time): Document new behaviour.
	(-ftoplevel-reorder): Document that it is enabled -O0 and imply
	-fno-section-anchors when disabled explicitly.
	(inline params): They are not ignored now.
	(precompiled headers): Remove unit-at-a-time as being incompatible.
	* opts.c (decode_options): Handle unit-at-a-time as alias;
	imply -fno-section-anchors when toplevel reorder is disabled
	explicitly.
	* common.opt (ftoplevel-reorder): Set default value to 2.
	(funit-at-a-time): Set default value to 1.
	* config/rs6000/rs6000.c (optimization_options): Set section anchors
	to 2.

From-SVN: r138009