devtools/reduce-includes.sh: brute-force script to remove includes.

Tries one at a time.  Slow, but doesn't need to be run often.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

devtools/reduce-includes.sh

@@ -0,0 +1,32 @@
+#! /bin/sh -e
+
+if [ $# -lt 1 ]; then
+    echo "Usage: $0 <cfilepath>...; removes #includes one at a time and checks compile" >&2
+    exit 1
+fi    
+
+CCMD=$(make show-flags | sed -n 's/CC://p')
+for file; do
+    i=1
+    echo "$file":
+    while true; do
+	# Don't eliminate config.h includes!
+	LINE="$(grep '^#include <' "$file" | grep -v '[<"]config.h[">]' | tail -n +$i | head -n1)"
+	[ -n "$LINE" ] || break
+	# Make sure even headers end in .c
+	grep -F -v "$LINE" "$file" > "$file".c
+
+	if $CCMD /tmp/out.$$.o "$file".c 2>/dev/null; then
+	    # shellcheck disable=SC2039
+	    echo -n "-$LINE"
+	    mv "$file".c "$file"
+	else
+	    # shellcheck disable=SC2039
+	    echo -n "."
+	    rm -f "$file".c
+	    i=$((i + 1))
+	fi
+	rm -f /tmp/out.$$.o
+    done
+    echo
+done