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 commit switches to LLVM 11 for builds with LLVM linked statically
(e.g. `make`). It does not yet switch the default for builds dynamically
linked to LLVM, that should be done in a later change.
This commit also changes to use the default host toolchain (probably
GCC) instead of Clang as the default compiler in CI. There were some
issues with Clang 3.8 in CI and hopefully this will fix it.
Additionally it updates the way LLVM is built on Windows, with
-DLLVM_ENABLE_PIC=OFF (which should have been used all along). This
change makes it possible to revert a hack to build libclang manually and
instead uses the libclang static library like on all other operating
systems, simplifying the Makefile.
This commit also adds a bit of version independence, in particular for
external commands. It also adds the LLVM version to the `tinygo version`
command, which might help while debugging.
