Fix some Perl array tests

[Mingun]

This PR fixes the following tests from the latest run

[info] - perl:[0, 1, 100500] *** FAILED ***
[info]   "[[0, 1, 100500]]" was not equal to "[(0, 1, 100500)]" (TranslatorSpec.scala:718)
[info]   Analysis:
[info]   "[[0, 1, 100500]]" -> "[(0, 1, 100500)]"
...
[info] - perl:a[42] *** FAILED ***
[info]   no expected result, but actual result is @{$self->a()}[42] (TranslatorSpec.scala:720)
...
[info] - perl:a[42 - 2] *** FAILED ***
[info]   no expected result, but actual result is @{$self->a()}[(42 - 2)] (TranslatorSpec.scala:720)
...
[info] - perl:a.first *** FAILED ***
[info]   no expected result, but actual result is @{$self->a()}[0] (TranslatorSpec.scala:720)
...
[info] - perl:a.last *** FAILED ***
[info]   no expected result, but actual result is @{$self->a()}[-1] (TranslatorSpec.scala:720)
[info] - perl:a.size *** FAILED ***
[info]   "scalar([@{$self->a()}])" was not equal to "scalar([$self->a()])" (TranslatorSpec.scala:718)
[info]   Analysis:
[info]   "scalar([@{$self->a()}])" -> "scalar([$self->a()])"
...
[info] - perl:"12345".to_i *** FAILED ***
[info]   ""12345"[ + 0]" was not equal to ""12345"[]" (TranslatorSpec.scala:718)
[info]   Analysis:
[info]   ""12345"[ + 0]" -> ""12345"[]"
...
[info] - perl:[].as<u1[]> *** FAILED ***
[info]   "[[]]" was not equal to "[()]" (TranslatorSpec.scala:718)
[info]   Analysis:
[info]   "[[]]" -> "[()]"
...
[info] - perl:[].as<f8[]> *** FAILED ***
[info]   "[[]]" was not equal to "[()]" (TranslatorSpec.scala:718)
[info]   Analysis:
[info]   "[[]]" -> "[()]"
...
[info] - perl:[0, 1, 2].as<u1[]> *** FAILED ***
[info]   "[[0, 1, 2]]" was not equal to "[(0, 1, 2)]" (TranslatorSpec.scala:718)
[info]   Analysis:
[info]   "[[0, 1, 2]]" -> "[(0, 1, 2)]"

Note: I do not known Perl, but those issues seems easy to fix

[generalmimon]

Looks good to me, thanks @Mingun!

Note: arrays in square brackets [] are indeed correct in Perl, as @dgburr explains in detail in #251 (comment).