[Bug] Anomaly in array type parsing

[acoglio]

Maybe not a (serious) bug, but at least anomalous behavior.

This works

cast r5 into r7 as /* comment */ [u8; 10u32];

while this does not work

cast r5 into r7 as /* comment */ u8;

The culprit is this line, which parses comments and whitespace at the beginning of an array type. Array types are one of three kind of plaintext types, the other two being literal types and identifiers: neither the parser of literal types nor the parser for identifiers parse comment and whitespace at the beginning; their callers parse whitespace (not comments). So the proposal is to remove the culprit line, and treat array types the same as the other plaintext types when parsing.