Safari / Chrome discrepancies lead to problems in instantiateWasm implementation example; Uncatchable exceptions in receiveInstance

These are two errors of two different modules (compiled under Emscripten 2.0.26):
```
[Error] Unhandled Promise Rejection: TypeError: undefined is not an object (evaluating 'Module["asm"]["oa"]')
receiveInstance (busybox_unstripped.js:9:10785)
promiseReactionJob

[Error] Unhandled Promise Rejection: TypeError: undefined is not an object (evaluating 'Module['asm']['memory']')
receiveInstance (busytex.js:1734)
promiseReactionJob
```

I'm initialising module as:
```js
instantiateWasm(imports, successCallback)
{
WebAssembly.instantiate(wasm_module, imports).then(successCallback);
},
```
where `wasm_module` is `ArrayBuffer` (under Safari).

1. How do I make it work under Safari? :)

2. Also for some reason these Unhandled Promise Rejections do not lead to exceptions. I'm using modularised Emscripten module, so I'm doing try-catch, and await inside try. Would you know why it's not failing with an exception and how to at least handle this gracefully?