[nqp]: Add --parsetrace option to nqp.

src/NQP/Compiler.pir

@@ -27,6 +27,8 @@ NQP::Compiler - NQP compiler
     nqpproto.'parsegrammar'($P0)
     $P0 = get_hll_global ['NQP'], 'Actions'
     nqpproto.'parseactions'($P0)
+    $P0 = split ' ', 'e=s help|h target=s dumper=s trace|t=s encoding=s output|o=s combine version|v parsetrace'
+    setattribute nqpproto, '@cmdoptions', $P0
 .end
 
 .sub 'main' :main

src/Regex/Cursor.pir

@@ -163,6 +163,7 @@ If C<regex> is omitted, then use the C<TOP> rule for the grammar.
     .param pmc regex           :optional
     .param int has_regex       :opt_flag
     .param pmc action          :named('action') :optional
+    .param int rxtrace         :named('rxtrace') :optional
     .param pmc options         :slurpy :named
 
     if has_regex goto regex_done
@@ -173,6 +174,9 @@ If C<regex> is omitted, then use the C<TOP> rule for the grammar.
 
     .local pmc cur, match
     cur = self.'!cursor_init'(target, options :flat :named)
+    unless rxtrace goto rxtrace_done
+    cur.'DEBUG'()
+  rxtrace_done:
     cur = cur.regex()
     match = cur.'MATCH'()
     .return (match)

src/cheats/hll-compiler.pir

@@ -24,7 +24,9 @@
     parseactions = self.'parseactions'()
   have_parseactions:
 
-    match = parsegrammar.'parse'(source, 'from'=>0, 'action'=>parseactions)
+    .local int rxtrace
+    rxtrace = options['parsetrace']
+    match = parsegrammar.'parse'(source, 'from'=>0, 'action'=>parseactions, 'rxtrace'=>rxtrace)
     unless match goto err_parsefail
     .return (match)