Merge branch 'kn/meson-hdr-check'

Add an equivalent to "make hdr-check" target to meson based builds.

* kn/meson-hdr-check:
  makefile/meson: add 'check-headers' as alias for 'hdr-check'
  meson: add support for 'hdr-check'
  meson: rename 'third_party_sources' to 'third_party_excludes'
  meson: move headers definition from 'contrib/coccinelle'
  coccinelle: meson: rename variables to be more specific
  ci/github: install git before checking out the repository

Makefile

@@ -3334,8 +3334,10 @@ HCC = $(HCO:hco=hcc)
 $(HCO): %.hco: %.hcc $(GENERATED_H) FORCE
 	$(QUIET_HDR)$(CC) $(ALL_CFLAGS) -o /dev/null -c -xc $<
 
-.PHONY: hdr-check $(HCO)
+# TODO: deprecate 'hdr-check' in lieu of 'check-headers' in Git 2.51+
+.PHONY: hdr-check check-headers $(HCO)
 hdr-check: $(HCO)
+check-headers: hdr-check
 
 .PHONY: style
 style: