Update to LLVM 15 (envoyproxy#54)

buildtools/wasi-sdk/Dockerfile

@@ -6,22 +6,22 @@ FROM debian:11-slim
 RUN apt-get update && apt-get install -y curl gnupg make
 
 RUN curl -sS https://apt.llvm.org/llvm-snapshot.gpg.key | gpg --dearmor > /etc/apt/trusted.gpg.d/llvm.gpg && \
-    echo "deb [signed-by=/etc/apt/trusted.gpg.d/llvm.gpg] http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye-14 main" >> /etc/apt/sources.list.d/llvm.list && \
-    echo "deb-src [signed-by=/etc/apt/trusted.gpg.d/llvm.gpg] http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye-14 main" >> /etc/apt/sources.list.d/llvm.list
+    echo "deb [signed-by=/etc/apt/trusted.gpg.d/llvm.gpg] http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye-15 main" >> /etc/apt/sources.list.d/llvm.list && \
+    echo "deb-src [signed-by=/etc/apt/trusted.gpg.d/llvm.gpg] http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye-15 main" >> /etc/apt/sources.list.d/llvm.list
 
-RUN apt-get update && apt-get install -y clang-14 lld-14
+RUN apt-get update && apt-get install -y clang-15 lld-15
 
 ADD https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-16/wasi-sysroot-16.0.tar.gz /
 RUN tar -xf wasi-sysroot-16.0.tar.gz
 
 ADD https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-16/libclang_rt.builtins-wasm32-wasi-16.0.tar.gz /
-RUN tar -xf libclang_rt.builtins-wasm32-wasi-16.0.tar.gz -C /usr/lib/llvm-14/lib/clang/14.0.6/
+RUN tar -xf libclang_rt.builtins-wasm32-wasi-16.0.tar.gz -C /usr/lib/llvm-15/lib/clang/15.0.3/
 
-ENV CC clang-14
-ENV CXX clang++-14
-ENV LD wasm-ld-14
-ENV AR llvm-ar-14
-ENV RANLIB llvm-ranlib-14
+ENV CC clang-15
+ENV CXX clang++-15
+ENV LD wasm-ld-15
+ENV AR llvm-ar-15
+ENV RANLIB llvm-ranlib-15
 ENV CFLAGS -O3 --target=wasm32-wasi --sysroot=/wasi-sysroot
 ENV CXXFLAGS -O3 -fno-exceptions --target=wasm32-wasi --sysroot=/wasi-sysroot
 ENV LDFLAGS ${CXXFLAGS} --rtlib=compiler-rt -Wl,--demangle,--allow-undefined