fixes the problem with --target=parse #nqp

gistfile1.diff

--- a/src/Perl6/Grammar.pm
+++ b/src/Perl6/Grammar.pm
@@ -428,7 +428,7 @@ grammar Perl6::Grammar is HLL::Grammar {
             unless pir::defined(%*COMPILING<%?OPTIONS><outer_ctx>) {
                 $*SETTING := $*W.load_setting(%*COMPILING<%?OPTIONS><setting> // 'CORE');
             }
-            $/.CURSOR.unitstart();
+            Perl6::Actions.unitstart($/);
             try {
                 my $EXPORTHOW := $*W.find_symbol(['EXPORTHOW']);
                 for $EXPORTHOW.WHO {