Will Anderson
beb2a8c5bd
try { ... } catch (name: Type) { ... } is now a first-class El statement.
Lexer: `try` and `catch` are now keywords (Try, Catch token kinds).
Parser: TryCatch AST node with try_body, catch_name, catch_body.
codegen-js: emits try { ... } catch (name) { ... } directly -- correct
for all browser error handling patterns.
codegen.el (C backend): emits the try body with a comment; exception
handling is a no-op since C has no analogous mechanism. Programs using
try/catch should compile with --target=js.
The catch variable type annotation is parsed and skipped (same treatment
as all other type annotations in El).