Isaac Freund b988815bf0 parser: fix parsing/rendering of a[b.. :c] slicing
The modification to the grammar in the comment is in line with the
grammar in the zig-spec repo.

Note: checking if the previous token is a colon is insufficent to tell
if a block has a label, the identifier must be checked for as well. This
can be seen in sentinel terminated slicing: `foo[0..1:{}]`
2021-03-08 01:37:28 +01:00
..
2020-12-04 15:39:16 -07:00
2021-02-10 13:38:16 -08:00