Rollup merge of #106644 - alexcrichton:update-wasi-toolchain, r=cuviper

Update the wasi-libc used for the wasm32-wasi target

This commit updates the wasi-libc revision used to build with the wasm32-wasi target. This notably pulls in WebAssembly/wasi-libc#377 which is needed to fix a use case I've been working on recently. This should be a relatively small update hopefully and is not expected to have any user impact.