Lexer: adds :nl (newline-before) boolean to every token. scan! resets the flag
before each skip-ws! call; skip-ws! sets it true when it consumes \n or \r.
Parser: jp-token-nl? reads the flag; jp-parse-return-stmt stops before the
expression when a newline precedes it (return\n42 → return undefined). Four
new tests cover the restricted production and the raw flag.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
giles
ae86579ae8