(state::is_unmerged_ret_state): Handle case where stacktop is
	NO_STACK.
	(state::merge): Handle NO_STACK merges.
	(handle_jsr_insn): Invalidate PC, and use special NO_STACK state
	for instruction following jsr.
	(stacktop, stackdepth): Removed unused variables.
	(pop_jump): Ignore case where all remaining states are skipped.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@50526 138bc75d-0d04-0410-961f-82ee72b054a4