Hi,
This patch renames remove_dead_inserted_code to simple_dce_from_worklist, moves it to tree-ssa-dce.c
and makes it a simple public DCE interface.  Bootstrap and test along with loop interchange.  It's required
for interchange pass.  Is it OK?
BTW, I will push this along with interchange to branch: gcc.gnu.org/svn/gcc/branches/gimple-linterchange.

Thanks,
bin
2017-11-27  Bin Cheng  <bin.cheng@arm.com>

	* tree-ssa-dce.c (simple_dce_from_worklist): Move and rename from
	tree-ssa-pre.c::remove_dead_inserted_code.
	* tree-ssa-dce.h: New file.
	* tree-ssa-pre.c (tree-ssa-dce.h): Include new header file.
	(remove_dead_inserted_code): Move and rename to function
	tree-ssa-dce.c::simple_dce_from_worklist.
	(pass_pre::execute): Update use.