Switch over to LLVM 14 for static builds. Keep using LLVM 13 for regular
builds for now.
This uses a branch of the upstream Espressif branch to fix an issue,
see: https://github.com/espressif/llvm-project/pull/59
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.
This makes sure that the LLVM target features match the one generated by
Clang:
- This fixes a bug introduced when setting the target CPU for all
targets: Cortex-M4 would now start using floating point operations
while they were disabled in C.
- This will make it possible in the future to inline C functions in Go
and vice versa. This will need some more work though.
There is a code size impact. Cortex-M4 targets are increased slightly in
binary size while Cortex-M0 targets tend to be reduced a little bit.
Other than that, there is little impact.
This LLVM version breaks CI and is now relatively rather old anyway, so
remove support for it.
This also reverts a workaround for LLVM 9, see a9568932b ("maixbit:
workaround to avoid medium code model").
This is needed to avoid linking errors because the globals are placed
in memory at address 0x80000000 which is out of bounds for the default
code model.
