JSX Tracing

[guybedford]

Since JSX / TSX support was added, the es-module-lexer doesn't have full JSX parser capabilities.

We should do a preparse of JSX files before the lexer by detecting the .jsx or .tsx extensions and running a very lightweight JSX transform before performing the analysis. Most likely we should just do a Babel parse to get the import list instead of using es-module-lexer in this case.

Extending es-module-lexer to support JSX via the grammar at https://facebook.github.io/jsx/ is another possibility.