CI: Switch from LLVM 12 to 14

The primary motivation for doing so is to avoid using Homebrew's `llvm@12`
package, which appears to now be broken (#1255).

Fixes #1255.

.github/Dockerfile-crux-llvm

@@ -7,7 +7,7 @@ RUN apt-get update && \
       # Crux dependencies \
       pkg-config zlib1g-dev \
       # LLVM toolchain
-      clang-12 llvm-12-tools \
+      clang-14 llvm-14-tools \
       # Miscellaneous
       locales unzip wget
 RUN sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && \
@@ -45,7 +45,7 @@ ADD crux-llvm ${DIR}/build/crux-llvm
 ADD dependencies ${DIR}/build/dependencies
 ADD .github/cabal.project.crux-llvm ${DIR}/build/cabal.project
 ADD cabal.GHC-9.4.8.config ${DIR}/build/cabal.project.freeze
-# Workaround until we have an LLVM 12 build available
+# Workaround until we have an LLVM 14 build available
 RUN cp $DIR/build/crux-llvm/c-src/libcxx-7.1.0.bc $DIR/build/crux-llvm/c-src/libcxx-12.0.1.bc
 
 WORKDIR ${DIR}/build

.github/ci.sh

@@ -64,13 +64,13 @@ test() {
 
 install_llvm() {
   if [[ "$RUNNER_OS" = "Linux" ]]; then
-    sudo apt-get update -q && sudo apt-get install -y clang-12 llvm-12-tools
-    echo "LLVM_LINK=llvm-link-12" >> "$GITHUB_ENV"
-    echo "LLVM_AS=llvm-as-12" >> "$GITHUB_ENV"
-    echo "CLANG=clang-12" >> "$GITHUB_ENV"
+    sudo apt-get update -q && sudo apt-get install -y clang-14 llvm-14-tools
+    echo "LLVM_LINK=llvm-link-14" >> "$GITHUB_ENV"
+    echo "LLVM_AS=llvm-as-14" >> "$GITHUB_ENV"
+    echo "CLANG=clang-14" >> "$GITHUB_ENV"
   elif [[ "$RUNNER_OS" = "macOS" ]]; then
-    brew install llvm@12
-    echo "$(brew --prefix)/opt/llvm@12/bin" >> "$GITHUB_PATH"
+    brew install llvm@14
+    echo "$(brew --prefix)/opt/llvm@14/bin" >> "$GITHUB_PATH"
   elif [[ "$RUNNER_OS" = "Windows" ]]; then
     choco install llvm
   else