build: Rename wasi-threads to wasip1-threads

The WASI community is transitioning to a new naming for the "preview"
version in the target triple: wasm32-wasi -> wasm32-wasip1.
At this moment, we keep the old triple wasm32-wasi because it's already
widely used, but we should start using the new triple threaded target.

LLVM checks only if the OS field *starts* with "wasi", so "wasip1" is
still considered a valid `isOSWASI()` target.

See: WebAssembly/wasi-libc#478

cmake/modules/SwiftConfigureSDK.cmake

@@ -423,7 +423,7 @@ macro(configure_sdk_unix name architectures)
  endif()
  set(SWIFT_SDK_WASI_ARCH_wasm32_PATH "${SWIFT_WASI_SYSROOT_PATH}")
  if(SWIFT_ENABLE_WASI_THREADS)
- set(SWIFT_SDK_WASI_ARCH_wasm32_TRIPLE "wasm32-unknown-wasi-threads")
+ set(SWIFT_SDK_WASI_ARCH_wasm32_TRIPLE "wasm32-unknown-wasip1-threads")
  else()
  set(SWIFT_SDK_WASI_ARCH_wasm32_TRIPLE "wasm32-unknown-wasi")
  endif()

utils/swift_build_support/swift_build_support/products/wasisysroot.py

@@ -143,7 +143,7 @@ def _build(self, host_target, enable_wasi_threads=False):
  'libcxx;libcxxabi;compiler-rt')
  libdir_suffix = '/wasm32-wasi'
  if enable_wasi_threads:
- libdir_suffix = '/wasm32-wasi-threads'
+ libdir_suffix = '/wasm32-wasip1-threads'
  self.cmake_options.define('LIBCXX_LIBDIR_SUFFIX:STRING', libdir_suffix)
  self.cmake_options.define('LIBCXXABI_LIBDIR_SUFFIX:STRING', libdir_suffix)
  self.cmake_options.define('CMAKE_STAGING_PREFIX:PATH', '/')
@@ -183,7 +183,7 @@ def _build(self, host_target, enable_wasi_threads=False):
  self.cmake_options.define('CMAKE_C_FLAGS:STRING', ' '.join(c_flags))
  self.cmake_options.define('CMAKE_CXX_FLAGS:STRING', ' '.join(cxx_flags))
 
- target_triple = 'wasm32-wasi-threads' if enable_wasi_threads else 'wasm32-wasi'
+ target_triple = 'wasm32-wasip1-threads' if enable_wasi_threads else 'wasm32-wasi'
  self.cmake_options.define('CMAKE_C_COMPILER_TARGET:STRING', target_triple)
  self.cmake_options.define('CMAKE_CXX_COMPILER_TARGET:STRING', target_triple)