nqp-rx fix for contextuals

gistfile1.md

In NQP, all variables get declared at the beginning of the block. This makes the following code fail:

my $old  := $*VAR;
my $*VAR := $new;

Instead of the old (outer) value of the contextual $*VAR, $old contains Undef. The following one line fix to nqp-rx seems to solve this problem by making NQP declare variables at the same point in the generated PIR as they are in the NQP code.

gistfile2.diff

diff --git i/src/NQP/Actions.pm w/src/NQP/Actions.pm
index d7c7602..2aba92a 100644
--- i/src/NQP/Actions.pm
+++ w/src/NQP/Actions.pm
@@ -438,7 +438,7 @@ method variable_declarator($/) {
                                    :lvalue(1), :viviself( vivitype($sigil) ),
                                    :node($/) );
         $BLOCK.symbol($name, :scope($scope) );
-        $BLOCK[0].push($decl);
+        $BLOCK.push($decl);
     }
     make $past;
 }