[krodak]

Overview

A @JS struct with a throws(JSException) or async @JS init produced Swift glue that did not compile. The generated bridgeJSStackPop() calls the @JS init to rebuild struct values that come from JavaScript, and that call has no try or await:

@_spi(BridgeJS) @_transparent public static func bridgeJSStackPop() -> Point {
    let x = Double.bridgeJSStackPop()
    return Point(x: x) // error: call can throw but is not marked with 'try'
}

A lift cannot fail, so BridgeJS now reports a diagnostic on such an initializer instead of generating code that does not build.

Testing

Added a diagnostics test for a throwing struct initializer. BridgeJS tests pass.