This means that it will be possible to generate a Darwin binary on any
platform (Windows, Linux, and MacOS of course), including CGo. Of
course, the resulting binaries can only run on MacOS itself.
The binary links against libSystem.dylib, which is a shared library. The
macos-minimal-sdk repository contains open source header files and
generated symbol stubs so we can generate a stub libSystem.dylib without
copying any closed source code.
This would conflict with our own heap. We previously defined all those
functions to make sure it's not used, but with a more recent wasi-libc
version (https://github.com/WebAssembly/wasi-libc/pull/250) we can
simply not compile the wasi-libc heap, which is the proper fix.
This adds support for building with `-tags=llvm13` and switches to LLVM
13 for tinygo binaries that are statically linked against LLVM.
Some notes on this commit:
* Added `-mfloat-abi=soft` to all Cortex-M targets because otherwise
nrfx would complain that floating point was enabled on Cortex-M0.
That's not the case, but with `-mfloat-abi=soft` the `__SOFTFP__`
macro is defined which silences this warning.
See: https://reviews.llvm.org/D100372
* Changed from `--sysroot=<root>` to `-nostdlib -isystem <root>` for
musl because with Clang 13, even with `--sysroot` some system
libraries are used which we don't want.
* Changed all `-Xclang -internal-isystem -Xclang` to simply
`-isystem`, for consistency with the above change. It appears to
have the same effect.
* Moved WebAssembly function declarations to the top of the file in
task_asyncify_wasm.S because (apparently) the assembler has become
more strict.