Fix: get wasi versions right

[uuhan]

Description

The following sample code should have the right wasi_version.

(module
  (type (;0;) (func (param i32 i32 i32 i32) (result i32)))
  (type (;1;) (func (param i32 i32 i32 i32)))
  (import "wasi_snapshot_preview1" "fd_write" (func (;0;) (type 0)))
  (import "env" "abort" (func (;1;) (type 1)))
)

Related Issue: #2226

[uuhan]

OK, I find another related pr #1028 which introduces a strict parameter.

So, what is the expected beheavior? If I have two module named wasi_snapshot_preview1 and env, wasmer complaints wasi_snapshot_preview1 not found.

Quite confusing.

I think, as the function's name shows, get_wasi_versions() should return the supported wasi-version we found in the module. There is no need to have a strict parameter to mix the logic. Give the choice to the caller to decide what to do with the found versions.

@MarkMcCaskey

[jcaesar]

uuhan: If you have symbols from both env. and wasi_snapshot_preview1., then that is probably code compiled by a not-that-old version of emscripten (e.g. > 1.39.20, iirc), which mixes its own custom interface with wasi_snapshot_preview1-like calls. Problem with that is: The emscripten env. stuff is not sandboxed, but wasmer implements wasi calls sandboxed.
So to support that kind of emscripten-generated binary, you'd need a non-sandboxed version of wasi, which is an entirely different problem… (right?)