Source Map Support

[cretz]

Support source maps. The problem is the JVM only supports a single SourceFile attribute. So I'm thinking maybe use SourceDebugAttribute to store filename-to-method map, then use "" as the SourceFile then maybe provide some runtime thing to translate stack traces. Or maybe, add an attribute on top of each method saying what source file it comes from (but has to be runtime visible). Or maybe, add a static method on the module that will translate method + line number to source file + line number. Actually, that would just translate method name to source file name, because line number would already be accurate.

[cretz]

This is essentially what https://stackoverflow.com/questions/11250834/how-to-add-jsr-045-smap-information-to-java-stacktraces-at-runtime means wrt https://jcp.org/en/jsr/detail?id=45. So, yeah, an opt-in that would store this information as the JSR mentions and/or in another source map form, and maybe a static method as mentioned that would do the translate.