Fixes#6894
The TypeScript parser now correctly detects preprocessor functions
that are re-exported from other modules using named exports like:
export { preprocessor } from "./other_module";
Previously, only function declarations were detected. Now the parser
also checks ExportNamed AST nodes for any specifier named 'preprocessor'.
This allows developers to easily reuse preprocessor functions across
multiple scripts without the workaround of wrapping them in a new function.
Added comprehensive tests covering:
- Simple re-export: export { preprocessor } from "./other"
- Re-export with renaming: export { preprocessor as preprocessor }
- Mixed exports: export { foo, preprocessor, bar }
- Negative case: exports without preprocessor
