C API: u8 in Rust corresponds to unsigned char* in C

[dannywillems]

Description

wasm_memory_data returns type is *mut u8 which corresponds in C to unsigned char *. byte_t is used in the C API to represent *mut u8 but it is an alias for char.
When compiling, we get the following warning:

warning: pointer targets in initialization of ‘uint8_t *’ {aka ‘unsigned char *’} from ‘byte_t *’ {aka ‘char *’} differ in signedness [-Wpointer-sign]
  572 |    uint8_t* x420 = wasm_memory_data(x419);

This MR changes the return type from byte_t to unsigned char.

[ptitSeb]

Ah yes, good catch.

[dannywillems]

I would suggest to add the flags -Wall -Wextra in the tests.

[syrusakbary]

We can't move from the standard wasm.h headers or used types.

If you want to change the wasm.h header file, I'd suggest making it a PR to the main wasm-c-api repo:
https://github.com/WebAssembly/wasm-c-api/blob/main/include/wasm.h#L478

[syrusakbary]

We can't merge this as this file is just a mirror of:
https://github.com/WebAssembly/wasm-c-api/blob/main/include/wasm.h#L478

[dannywillems]

We can't merge this as this file is just a mirror of: https://github.com/WebAssembly/wasm-c-api/blob/main/include/wasm.h#L478

See WebAssembly/wasm-c-api#179

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[syrusakbary]

Closing this as stale, but feel free to reopen the PR once wasm-c-api merges this upstream