[perl #120831] [BUG] LTA error message when declaring 'my Int a' in Rakudo

[Tobias Leich via RT]

Patch by bartolin++: 
https://github.com/rakudo/rakudo/commit/4bdc88046ad0289f2708e3195e59df9edc83c258
Another test: https://github.com/perl6/roast/commit/1145029340

Closing ticket.