* Update how wasi-sdk uses cmake
Change `CMAKE_SYSTEM_NAME` to `WASI`, use a `CMAKE_MODULE_PATH`,
remove `CACHE` usage, and fix the compiler autodetection code so that
the "compiler works" hacks are no longer needed, following the advice in
[this comment](https://gitlab.kitware.com/cmake/cmake/-/issues/19223#note_567327).
This is hopefully a step towards re-submitting WASI support to upstream cmake.
* Add --sysroot to compiler-rt's C flags.
This ensures that it finds the built sysroot when testing whether the C
compiler works.
* Fixes.
* Use the just-built ar rather than the host ar.
* Use -DCMAKE_C_COMPILER_WORKS=ON instead of stubbing out archive files.
* Use -DCMAKE_CXX_COMPILER_WORKS=ON too.
* Restore the `--sysroot` argument when building compiler-rt.
compiler-rt depends on some libc headers, so it needs a sysroot.
* Add sysroot arguments for libc++ and libc++abi too.
* Also set CMAKE_AR.
It appears with the removal of the AR checks cmake is no longer
autodetecting CMAKE_AR, so set it explicitly.
* Remove --no-threads from wasi-sdk.cmake.
It was added to work around this bug:
https://bugs.llvm.org/show_bug.cgi?id=41508
which was fixed in LLVM 9.0.
* Remove LLVM 8.0 workarounds.
* Make build work on Windows
* re-enable windows build workflow
* fix make check
* fix tar_from_installation.sh and dist target
* Review fixups
* No -j4 on Windows
* Get rid of -j4 everywhere in Makefile
This renames /opt/wasi/share/sysroot to /opt/wasi/share/wasi-sysroot.
If the user selects an alternate prefix, this allows wasi-sysroot to
coexist with other packages with less risk of namespace collision. For
example, if the user uses a prefix of /usr/local, this avoids using
/usr/local/share/sysroot, which is fairly generic, and uses
/usr/local/share/wasi-sysroot, which more clearly indicates its purpose.
Dan Gohman
Dan Gohman
Vladimir Vukicevic
Pat Hickey