Merge branch 'ab/coccicheck-incremental'

"make coccicheck" is time consuming. It has been made to run more
incrementally.

* ab/coccicheck-incremental:
  Makefile: don't create a ".build/.build/" for cocci, fix output
  spatchcache: add a ccache-alike for "spatch"
  cocci: run against a generated ALL.cocci
  cocci rules: remove <id>'s from rules that don't need them
  Makefile: copy contrib/coccinelle/*.cocci to build/
  cocci: optimistically use COMPUTE_HEADER_DEPENDENCIES
  cocci: make "coccicheck" rule incremental
  cocci: split off "--all-includes" from SPATCH_FLAGS
  cocci: split off include-less "tests" from SPATCH_FLAGS
  Makefile: split off SPATCH_BATCH_SIZE comment from "cocci" heading
  Makefile: have "coccicheck" re-run if flags change
  Makefile: add ability to TAB-complete cocci *.patch rules
  cocci rules: remove unused "F" metavariable from pending rule
  Makefile + shared.mak: rename and indent $(QUIET_SPATCH_T)

diff --cc .gitignore
Simple merge

diff --cc Makefile
Simple merge