Update wasi-libc to latest (#560)

Pull in recent changes e.g. around wasip2 bits

.github/workflows/main.yml

@@ -164,9 +164,10 @@ jobs:
       - uses: ./.github/actions/checkout
       - uses: ./.github/actions/install-deps
       - run: cargo install wasm-component-ld@0.5.12
+      - run: sudo apt-get update -y && sudo apt-get install -y clang-20 lld-20
       - run: |
           cmake -G Ninja -B build -S . \
-            -DCMAKE_C_COMPILER=/usr/lib/llvm-18/bin/clang \
+            -DCMAKE_C_COMPILER=/usr/lib/llvm-20/bin/clang \
             -DCMAKE_SYSTEM_NAME=WASI \
             -DWASI_SDK_INCLUDE_TESTS=ON \
             -DWASI_SDK_CPU_CFLAGS="" \

src/llvm-project

@@ -1 +1 @@
-Subproject commit 87f0227cb60147a26a1eeb4fb06e3b505e9c7261
+Subproject commit 3623fe661ae35c6c80ac221f14d85be76aa870f1

src/wasi-libc

@@ -1 +1 @@
-Subproject commit 3f7eb4c7d6ede4dde3c4bffa6ed14e8d656fe93f
+Subproject commit bbb0c01b112f8c3aaa1974407c5302a26b88babb