Test nested enum coercion

Adds tests for RT#129142

S12-enums/basic.t

@@ -1,6 +1,6 @@
 use v6;
 use Test;
-plan 53;
+plan 54;
 
 # Very basic enum tests
 
@@ -252,4 +252,9 @@ is-deeply do { my enum Foos (a => <42>); a.Str }, 'a',
     'Pair elements in the list given to enum declaration work';
 }
 
+{ # RT #129142
+    eval-lives-ok 'my enum FF <zero one two three>; my enum GG <fee fie foo fum>; { FF(GG(2)).perl }',
+                  'Coercing an enum from a coercion of an enum from an int works';
+}
+
 # vim: ft=perl6