Fix crashes with compile time evalution of where thunks

Phixes #1465

When we compile_in_context, we rake the .ann('outer')s to find all
the good bits. However, the `where` thunks don't get that annotation
and so the raking stops prematurely. This causes the thunk that
tries to access some core symbols (like Junction ops) executed
during being time explode.

Fix by adding annotating the thunk with the current pad.

src/Perl6/Actions.nqp

@@ -9307,7 +9307,7 @@ class Perl6::Actions is HLL::Actions does STDActions {
                     :op('callmethod'), :name('ACCEPTS'),
                     $expr,
                     $operand,
-                )));
+                ))).annotate_self: 'outer', $*W.cur_lexpad;
         ($*W.cur_lexpad())[0].push($past);
 
         # Give it a signature and create code object.