[OSX] Update LLVM/clang to 15.0.3 (the latest x86_64 version)

Author: TheBlueMatt

.github/workflows/build.yml

@@ -347,14 +347,14 @@ jobs:
         run: rustup target install aarch64-apple-darwin
       - name: Fetch upstream LLVM/clang snapshot
         run: |
-          wget -O clang+llvm-14.0.5-x86_64-apple-darwin.tar.xz https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.5/clang+llvm-14.0.5-x86_64-apple-darwin.tar.xz
-          if [ "$(shasum -a 256 clang+llvm-14.0.5-x86_64-apple-darwin.tar.xz | awk '{ print $1 }')" != "66cf1b8e00289a567b2f5f740f068b7682e27ccf048647b836d3624376a64705" ]; then
+          wget -O clang+llvm-15.0.3-x86_64-apple-darwin.tar.xz https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.3/clang+llvm-15.0.3-x86_64-apple-darwin.tar.xz
+          if [ "$(shasum -a 256 clang+llvm-15.0.3-x86_64-apple-darwin.tar.xz | awk '{ print $1 }')" != "ac668586b2b3d068f1e43520a3ef0b1592e5dc3eff1a4a4b772e29803b428a69" ]; then
             echo "Bad hash"
             exit 1
           fi
       - name: Unpack upstream LLVM+clang and use it by default
         run: |
-          tar xvvf clang+llvm-14.0.5-x86_64-apple-darwin.tar.xz
+          tar xvvf clang+llvm-15.0.3-x86_64-apple-darwin.tar.xz
       - name: Checkout source code
         uses: actions/checkout@v2
         with:
@@ -375,7 +375,7 @@ jobs:
           git checkout 0.0.113
       - name: Rebuild C bindings with upstream clang, and check the sample app builds + links
         run: |
-          export PATH=`pwd`/clang+llvm-14.0.5-x86_64-apple-darwin/bin:$PATH
+          export PATH=`pwd`/clang+llvm-15.0.3-x86_64-apple-darwin/bin:$PATH
           cd ldk-c-bindings
           CC=clang ./genbindings.sh ../rust-lightning true
       - name: Fetch OpenJDK 18
@@ -414,7 +414,7 @@ jobs:
           export LDK_GARBAGECOLLECTED_GIT_OVERRIDE="$(git describe --tag HEAD)"
           export JAVA_HOME=`pwd`/jdk-18.0.1.1.jdk/Contents/Home
           export PATH=$JAVA_HOME/bin:$PATH
-          export PATH=`pwd`/clang+llvm-14.0.5-x86_64-apple-darwin/bin:$PATH
+          export PATH=`pwd`/clang+llvm-15.0.3-x86_64-apple-darwin/bin:$PATH
           ./genbindings.sh ./ldk-c-bindings/ "-I$JAVA_HOME/include/ -I$JAVA_HOME/include/darwin -isysroot$(xcrun --show-sdk-path)" false false
 
           if [ "${{ matrix.platform }}" = "macos-11" ]; then