2009-06-11  David Daney  <ddaney@caviumnetworks.com>

	PR c/39252
	* doc/extend.texi ( __builtin_unreachable): Document new builtin.
	* builtins.c (expand_builtin_unreachable): New function.
	(expand_builtin): Handle BUILT_IN_UNREACHABLE case.
	* builtins.def (BUILT_IN_UNREACHABLE): Add new builtin.
	* cfgcleanup.c (try_optimize_cfg): Delete empty blocks with no
	successors.
	* cfgrtl.c (rtl_verify_flow_info): Handle empty blocks when
	searching for missing barriers.

2009-06-11  David Daney  <ddaney@caviumnetworks.com>

	PR c/39252
	* gcc.dg/builtin-unreachable-1.c: New test.
	* gcc.dg/builtin-unreachable-2.c: Same.

From-SVN: r148403