1999-12-26  Zack Weinberg  <zack@wolery.cumb.org>

	* acconfig.h: New ENABLE flags: TREE_CHECKING, RTL_CHECKING,
	GC_CHECKING, GC_ALWAYS_COLLECT.
	* configure.in: Allow --enable-checking with an argument
	listing check modes to enable.
	* config.in, configure: Rebuilt.
	* ggc-page.c, ggc-simple.c: Define GGC_POISON (and
	GGC_ALWAYS_VERIFY for ggc-simple.c) only if
	ENABLE_GC_CHECKING.  Define GGC_ALWAYS_COLLECT only if
	ENABLE_GC_ALWAYS_COLLECT.
	* rtl.h, rtl.c: Change ENABLE_CHECKING to ENABLE_RTL_CHECKING
	throughout.
	* tree.h, tree.c: Change ENABLE_CHECKING to
	ENABLE_TREE_CHECKING throughout.

	* cp-tree.h: Replace ENABLE_CHECKING with ENABLE_TREE_CHECKING
	throughout.

From-SVN: r31093