roast files with "use experimental" in them

experimental.txt

% rak 'use experimental' t/spec --files-with-matches --stats
t/spec/6.c/S14-roles/mixin-6c.t
t/spec/S32-str/pack.t
t/spec/S32-str/unpack.t
t/spec/S06-macros/unquoting.t
t/spec/S06-macros/unquoting.rakudo.moar
t/spec/S06-macros/quasi-blocks.t
t/spec/S06-macros/quasi-blocks.rakudo.moar
t/spec/S06-macros/errors.t
t/spec/S06-macros/returning-string.t
t/spec/S06-macros/opaque-ast.t
t/spec/S06-macros/opaque-ast.rakudo.moar
t/spec/S06-macros/returning-closure.t
t/spec/S06-macros/postfix.t
t/spec/S06-signature/sub-ref.t
t/spec/S06-signature/sub-ref.rakudo.moar
t/spec/packages/Example/lib/Example/C.rakumod
t/spec/S14-roles/mixin-6e.t
t/spec/S32-exceptions/misc2.t
t/spec/S12-coercion/coercion-return.t
t/spec/S06-operator-overloading/circumfix.rakudo.moar
t/spec/S06-operator-overloading/circumfix.t
t/spec/S02-types/sigils-and-types.t
t/spec/S02-types/sigils-and-types.rakudo.moar
t/spec/S02-names/is_cached.t
t/spec/integration/advent2012-day23.t
t/spec/integration/99problems-41-to-50.t
t/spec/S03-operators/buf.t
t/spec/S26-documentation/why-leading.t
t/spec/S26-documentation/why-trailing.t
t/spec/S26-documentation/block-trailing.t
t/spec/S26-documentation/why-both.t
t/spec/S26-documentation/block-leading.t
t/spec/S26-documentation/why-trailing.rakudo.moar
t/spec/S04-declarations/will-complain.t
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Statistics for 'use experimental':
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    Number of files: 2004
    Number of lines: 384052
  Number of matches: 34