Fix QF_SLIA parsing errors

[joaomhmpereira]

Don't know if this way of propagating types is correct. It does get rid of parsing errors

[joaomhmpereira]

Had to do this for the re.inter operator:

| "re.inter", [ a; b ] -> Expr.raw_binop Ty_regexp Regexp_inter a b
| "re.inter", [ a; b; c ] ->
        Expr.raw_binop Ty_regexp Regexp_inter a
          (Expr.raw_binop Ty_regexp Regexp_inter b c)

Because, despite being considered a binary operator according to the SMT-LIB, some tests in the QF_SLIA benchmarks use it as a ternary operator.

[joaomhmpereira]

Currently passing 99.74% of tests from the QF_SLIA benchmarks

[filipeom]

I still haven't had time to check this. Hoping to get to it in the weekend