tool/run: introduce 'have_recipe'-proc

This procedure is useful for run scripts that depend for example on a
board support package that is provided only for certain boards, possibly
by a third-party repo.

Issue #5432

tool/run/run

@@ -955,6 +955,14 @@ proc have_include { name } {
 	return false
 }
 
+##
+# Check if a specific depot recipe is available
+#
+proc have_recipe { name } {
+	set hash_rel_path "recipes/$name/hash"
+	return [expr {[repository_contains $hash_rel_path] != ""}]
+}
+
 
 ##
 # Override the exit procedure