One minor thought I'd offer up is an option INI setting to disable creation of the opcode. This allows the #line directives to be used in dev/debug environments without causing an impact for production servers during execution. It's not a major performance hit, but it's something.
Why not leave it up to the user land code generator to include the directive in the debug version or generate without it in the production version?
Indeed. This suggestion was cross-wired with another thought when an enable/disable switch made more sense. For the sake of code-generators it does make more sense to simply not generate the line during pre-compile.