Path resolution should be consistent with WASI spec

[yagehu]

Currently, in functions such as path_open, uvwasi first normalizes the path. For example, a path such as a/./../a/b would be normalized to a/b before calling the underlying OS syscall.

This behavior is inconsistent with the WASI documentation, which specifies that path components should be resolved one by one.

This causes seemingly simple WASI calls to behave differently on Node (uvwasi) and many other runtimes like Wasmtime, WasmEdge, etc. For example, a path_open call that tries to create a file a/. will fail on Wasmtime while it succeeds on Node.

@cjihrig has previously suggested a path forward in #269. I just want to open a dedicated issue to track this.

[mhdawson]

I agree that improving consistently with the other runtimes would be good.