Merge upstream wasi-sdk (through wasi-sdk-33): C++ exceptions, libunwind, wasip2/p3

.github/actions/checkout/action.yml

@@ -0,0 +1,16 @@
+name: 'Prepare wasi-sdk git directory'
+description: 'Prepare wasi-sdk git directory'
+
+runs:
+  using: composite
+  steps:
+    - run: git fetch --tags --force
+      name: Force-fetch tags to work around actions/checkout#290
+      shell: bash
+    # We can't use `--depth 1` here sadly because the GNU config
+    # submodule is not pinned to a particular tag/branch. Please
+    # bump depth (or even better, the submodule), in case of "error:
+    # Server does not allow request for unadvertised object" in the
+    # future.
+    - run: git submodule update --init --depth 64 --jobs 3
+      shell: bash

.github/actions/install-deps/action.yml

@@ -0,0 +1,28 @@
+name: 'Install wasi-sdk dependencies'
+description: 'Install wasi-sdk dependencies'
+
+runs:
+  using: composite
+  steps:
+    - name: Setup `wasmtime` for tests
+      uses: bytecodealliance/actions/wasmtime/setup@v1
+      with:
+        version: "41.0.3"
+    - name: Install ccache, ninja (macOS)
+      run: brew install ccache ninja
+      if: runner.os == 'macOS'
+      shell: bash
+    - name: Install ccache, ninja (Windows)
+      run: choco install ccache ninja
+      if: startsWith(matrix.os, 'windows')
+      shell: bash
+      # Windows arm runners don't come with rust by default (see https://github.com/actions/partner-runner-images/blob/main/images/arm-windows-11-image.md)
+      # but the x86 ones do (see https://github.com/actions/runner-images/blob/main/images/windows/Windows2025-Readme.md)
+    - name: Install cargo (Windows-arm)
+      run: choco install rust
+      if: matrix.os == 'windows-11-arm'
+      shell: bash
+    - name: Install ccache, ninja (Linux)
+      run: sudo apt-get install -y ccache ninja-build
+      if: runner.os == 'Linux'
+      shell: bash