Polyfill doesn't work on Safari 12.1

[zhuowei]

When I try to run a WebAssembly file in the polyfill at https://wasi.dev/polyfill/, I get

"Exception thrown, see JavaScript console" when I try to load the file.

In the console, I get:

"WebAssembly.instantiateStreaming is not a function. (In 'WebAssembly.instantiateStreaming(response, imports)', 'WebAssembly.instantiateStreaming' is undefined)"

I'm on macOS 10.14.4, Safari 12.1 (Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.1 Safari/605.1.15).