Added an integer overflow check on literal values in the script parser

- When attempting to use a value greater than INT_MAX or smaller than
  INT_MIN (about +/- 2 billions), an error message will be shown and
  script execution will be aborted.
- Corrected some scripts that were attempting to use such values.
- Fixed some possible issues when using literal negative values in
  scripts.
Thanks to Ind for his help on this issue (figuring it out and fixing it)

Signed-off-by: Haru <haru@dotalux.com>
Added support for non-fatal error messages from the script parser

- Changed overflow errors to be non-fatal. The value will now be capped
  to INT_MAX or INT_MIN.
- Follow-up to 8351881

Signed-off-by: Haru <haru@dotalux.com>