* tree-flow.h: Include new .h files. Move prototypes.
* tree-cfgcleanup.h: New file. Add prototypes from tree-flow.h.
* tree-dfa.h: New File. Add prototypes from tree-flow.h.
(get_addr_base_and_unit_offset_1) Move from tree-flow-inline.h.
* tree-pretty-print.h: Add prototypes from tree-flow.h.
* tree-into-ssa.h: New File. Add prototypes from tree-flow.h.
({debug|dump}*): Move debugging prototypes out of tree-into-ssa.c.
* tree-into-ssa.c ({debug|dump}*): Move prototypes to header file.
* tree.h (get_ref_base_and_extent): Move prototype out.
* tree-flow-inline.h (get_addr_base_and_unit_offset_1): Move to
tree-dfa.h.
* gimple-low.h: New File. Add prototypes from tree-flow.h.
* gimple-low.c (try_catch_may_fallthru, block_may_fallthru): Move to...
* tree.c (try_catch_may_fallthru, block_may_fallthru): Here.
* tree-scalar-evolution.c: Include tree.h.
* sese.c: Include tree.h.
* dumpfile.c: Move gimple-pretty-print.h include after tree.h.
* dwarf2out.c: Include tree-dfa.h.
* tree-chrec.c: Include tree.h.
* tree-data-ref.c: Include tree.h.