meson: recreate dist-check-help

tools/meson-check-help.sh

@@ -0,0 +1,20 @@
+#!/bin/sh -e
+
+# output width
+if "$1"  --help | grep -v 'default:' | grep -E -q '.{80}.'; then
+    echo "$(basename "$1") --help output is too wide:"
+    "$1"  --help | awk 'length > 80' | grep -E --color=yes '.{80}'
+    exit 1
+fi
+
+# no --help output to stdout
+if "$1" --help 2>&1 1>/dev/null | grep .; then
+    echo "$(basename "$1") --help prints to stderr"
+    exit 2
+fi
+
+# error output to stderr
+if ! "$1" --no-such-parameter 2>&1 1>/dev/null | grep -q .; then
+    echo "$(basename "$1") with an unknown parameter does not print to stderr"
+    exit 3
+fi