[perl #131945] [LTA] Differring behaviours when using an outer-scope-declared var before declaring it in current scope

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# New Ticket Created by  Zoffix Znet 
# Please include the string:  [perl #131945]
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I'd expect all three have the same behaviour (likely the last one, that cries 
about already-bound symbols):


    my int $x = 42;
    { say $x; my int $x = 70; }
    # OUTPUT: 0 (no errors)

    my int $y = 42;
    { say $y; my $y = 70; }
    # OUTPUT:
    # ===SORRY!===
    # Cannot take a reference to a non-native lexical

    my $z = 42;
    { say $z; my $z = 70; }
    # ===SORRY!=== Error while compiling 
/home/zoffix/devbox/tmp/C/exercises/f.p6
    # Lexical symbol '$z' is already bound to an outer symbol;
    # the implicit outer binding must be rewritten as OUTER::<$z>
    # before you can unambiguously declare a new '$z' in this scope
    # at /home/zoffix/devbox/tmp/C/exercises/f.p6:12
    # ------>     { say $z; my $z⏏ = 70; }
    #     expecting any of:
    #         constraint