* cfgrtl.c (purge_all_dead_edges): Initialize variable.
	* dwarf2out.c (is_cxx): Prototype.
	* local-alloc.c (block_alloc): Avoid 'unsigned>=0 is always true'
	warning.
	* objc/objc-act.c (defer_fn): Avoid signed/unsigned warning.

From-SVN: r47528