cocci: split off "--all-includes" from SPATCH_FLAGS

Per the rationale in 7b63ea5750 (Makefile: remove mandatory "spatch"
arguments from SPATCH_FLAGS, 2022-07-05) we have certain flags that
are truly mandatory, such as "--sp-file" and "--patch .". The
"--all-includes" flag is also critical, but per [1] we might want to
ad-hoc tweak it occasionally for testing or one-offs.

But being unable to set e.g. SPATCH_FLAGS="--verbose-parsing" without
breaking how our "spatch" works isn't ideal, i.e. before this we'd
need to know about the default include flags, and specify:
SPATCH_FLAGS="--all-includes --verbose-parsing".

If we were then to change the default include flag (e.g. to
"--recursive-includes") in the future any such one-off commands would
need to be correspondingly updated.

Let's instead leave the SPATCH_FLAGS for the user, while creating a
new SPATCH_INCLUDE_FLAGS to allow for ad-hoc testing of the include
strategy itself.

1. https://lore.kernel.org/git/20220823095733.58685-1-szeder.dev@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

Makefile

@@ -1295,7 +1295,8 @@ SANITIZE_LEAK =
 SANITIZE_ADDRESS =
 
 # For the 'coccicheck' target
-SPATCH_FLAGS = --all-includes
+SPATCH_INCLUDE_FLAGS = --all-includes
+SPATCH_FLAGS =
 SPATCH_TEST_FLAGS =
 # Setting SPATCH_BATCH_SIZE higher will
 # usually result in less CPU usage at the cost of higher peak memory.
@@ -1305,6 +1306,7 @@ SPATCH_BATCH_SIZE = 1
 # Rebuild 'coccicheck' if $(SPATCH), its flags etc. change
 TRACK_SPATCH_DEFINES =
 TRACK_SPATCH_DEFINES += $(SPATCH)
+TRACK_SPATCH_DEFINES += $(SPATCH_INCLUDE_FLAGS)
 TRACK_SPATCH_DEFINES += $(SPATCH_FLAGS)
 TRACK_SPATCH_DEFINES += $(SPATCH_TEST_FLAGS)
 TRACK_SPATCH_DEFINES += $(SPATCH_BATCH_SIZE)
@@ -3177,6 +3179,7 @@ $(COCCI_PATCHES): %.patch: %
 	fi; \
 	if ! echo $(COCCI_SOURCES) | xargs $$limit \
 		$(SPATCH) $(SPATCH_FLAGS) \
+		$(SPATCH_INCLUDE_FLAGS) \
 		--sp-file $< --patch . \
 		>$@+ 2>$@.log; \
 	then \