fix(c-api) wasi_version_t wasn't bound correctly to C

[Hywan]

Description

Because the enum variants weren't in uppercase and because one variant (InvalidVersion) has a non-literal value, cbindgen was ignoring the variants. This patch fixes that. It's not a breaking changes since the WASI version constants weren't present in the wasmer_wasm.h file before.

Note: u32::max_value() is soft-deprecated, we should use u32::MAX instead. Notice that none of them works with cbindgen, so I've hardcoded the value of u32::MAX -1 (now) here.

Review

• Add a short description of the the change to the CHANGELOG.md file

[Hywan]

bors r+

[bors]

Build failed:

• Test on windows-x64

[Hywan]

Error on Windows (for the record):

D:\a\wasmer\wasmer\tests\integration\cli/../../../lib/c-api\wasmer_wasm.h:105:18: error: typedef redefinition with different types ('uint32_t' (aka 'unsigned int') vs 'wasi_version_t')
    typedef uint32_t wasi_version_t;
                     ^
    D:\a\wasmer\wasmer\tests\integration\cli/../../../lib/c-api\wasmer_wasm.h:70:6: note: previous definition is here
    enum wasi_version_t {

[Hywan]

7a435ef

On Windows, using a u32 representation for wasi_version_t fails if
a C++ compiler is used to treat a C program. So we change our strategy
here. We use a C representation to be FFI-safe, and the
INVALID_VERSION variant is now set to -1 instead of u32::MAX.

This patch also adds unit tests for wasi_get_wasi_version so that we
are sure of the behavior of this type on all platforms.

[Hywan]

bors r+

[bors]

Build succeeded:

• Audit
• Code lint
• Test cross-compile on linux
• Test cross-compile on macos
• Test on linux-aarch64
• Test on linux-x64
• Test on macos-x64
• Test on windows-x64