Bug: `pragma circom` panics the parser instead of emitting `P1003`

[anon-researchers-123]

Expected behavior

An out-of-range version pragma should emit error[P1003] (unsupported version),
exactly like an in-range-but-unsupported version already does.

The bug

A version number ≥ 2^64 panics the parser (exit code 101) instead of reporting P1003.

pragma circom 18446744073709551616.0.0;   // 2^64, panics

thread 'main' panicked at .../lang.rs: failed to parse number: ParseIntError { kind: PosOverflow }
circom exit status: 101

For contrast, pragma circom 18446744073709551615.0.0; (exactly usize::MAX) reports
P1003 cleanly.