[perl #74778] [BUG] Two occurences of $^a in a block mess with control flow

[via RT]

# New Ticket Created by  Stefan O'Rear 
# Please include the string:  [perl #74778]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=74778 >


# This prints gothere ONCE
# Removing either sink expression causes the correct two prints
# rakudo e16cf4
for 1, 2 {
    $^a;
    $^a;
    say "gothere";
}