scripts/clean-includes: Do all our exclusions with REGEXFILE

We currently have two mechanisms for excluding files:
 * the REGEXFILE which excludes by regex
 * special cases in the "loop over each file" which make
   us skip the file

Roll all the "skip this" cases into REGEXFILE, so we use
a single mechanism for identifying which files to exclude.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20260116124005.925382-5-peter.maydell@linaro.org

scripts/clean-includes

@@ -104,6 +104,15 @@ grep -v '^#' >"$REGEXFILE" <<EOT
 ^ebpf/rss.bpf.skeleton.h
 # These files just include some other .c file and have no content themselves
 ^linux-user/(mips64|x86_64)/(cpu_loop|signal).c
+# These are autogenerated headers
+^include/standard-headers/
+# osdep.h itself and its friends are expected to include system headers
+^include/qemu/osdep.h
+^include/qemu/compiler.h
+^include/glib-compat.h
+^include/system/os-(posix|win32).h
+# This is for use by plugins, which are standalone binaries
+^include/qemu/qemu-plugin.h
 EOT
 
 # We assume there are no files in the tree with spaces in their name
@@ -137,21 +146,6 @@ for f in "$@"; do
     *.c)
       MODE=c
       ;;
-    *include/qemu/osdep.h | \
-    *include/qemu/compiler.h | \
-    *include/qemu/qemu-plugin.h | \
-    *include/glib-compat.h | \
-    *include/system/os-posix.h | \
-    *include/system/os-win32.h | \
-    *include/standard-headers/ )
-      # Removing include lines from osdep.h itself would be counterproductive.
-      echo "SKIPPING $f (special case header)"
-      continue
-      ;;
-    *include/standard-headers/*)
-      echo "SKIPPING $f (autogenerated header)"
-      continue
-      ;;
     *.h)
       MODE=h
       ;;