Various cleanup with new -x option

Author: kddnewton

include/prism/util/pm_newline_list.h

@@ -63,6 +63,8 @@ bool pm_newline_list_init(pm_newline_list_t *list, const uint8_t *start, size_t
 
 /**
  * Clear out the newlines that have been appended to the list.
+ *
+ * @param list The list to clear.
  */
 void
 pm_newline_list_clear(pm_newline_list_t *list);

rakelib/lex.rake

@@ -86,7 +86,10 @@ TARGETS = {
   ruby: {
     repo: "https://github.com/ruby/ruby",
     sha: "52837fcec2340048f9bdc2169cde17243c5e9d6d",
-    excludes: ["spec/ruby/command_line/fixtures/bad_syntax.rb"]
+    excludes: [
+      "spec/ruby/command_line/fixtures/bad_syntax.rb",
+      "tool/merger.rb"
+    ]
   },
   discourse: {
     repo: "https://github.com/discourse/discourse",