warning: '+' is deprecated

[semireg]

Seeing these warnings.

InternalRegex.swift:93:37: warning: '+' is deprecated: Mixed-type addition is deprecated. Please use explicit type conversion.
          let start = Int(accOffset + regexMatches[j].rm_so)

InternalRegex.swift:94:35: warning: '+' is deprecated: Mixed-type addition is deprecated. Please use explicit type conversion.
          let end = Int(accOffset +   regexMatches[j].rm_eo)