[int_19h]

You're conflating C++/CLI with the MSVC /clr compiler switch. They're distinct.

With /clr:pure (which produces CIL only, although it is allowed to use memory-unsafe features like pointers), the entirety of ISO C90 is supported on CLR, with the sole exception of setjmp/longjmp.

C++/CLI adds language extensions that allow one to interact with the CLR object model from C++ code. It is only needed if you need to call into the .NET standard library, or other managed libraries - i.e. if your C code is not portable to begin with.

[Rusky]

I'm not conflating anything. And as I said, none of this is sandboxed like WebAssembly so it's hardly a comparison anyway.

[pjmlp]

Neither is WASM that allows for internal corruption due to lack of memory tagging.