CI: Revert to LDC-LLVM v19.1.7 due to remaining dynamic-compile regressions with LLVM 20

Author: kinke

.github/actions/1-setup/action.yml

@@ -23,7 +23,7 @@ runs:
 
         packages=( \
           git-core cmake g++ \
-          libcurl4 libzstd-dev \
+          libcurl4 libxml2-dev libzstd-dev \
           curl gdb p7zip-full tzdata unzip zip python3-pip \
         )
         if [[ $arch == x86_64 ]]; then
@@ -37,26 +37,26 @@ runs:
         # Make sure to link libzstd statically
         sudo rm /usr/lib/$arch-linux-gnu/libzstd.so
 
-    - name: 'Linux: Install clang 20 from apt.llvm.org'
+    - name: 'Linux: Install clang 19 from apt.llvm.org'
       if: runner.os == 'Linux'
       shell: bash
       run: |
         set -eux
         cd ..
         curl -fL --retry 3 --max-time 30 -O https://apt.llvm.org/llvm.sh
-        sudo bash llvm.sh 20
+        sudo bash llvm.sh 19
         for tool in clang clang++ ld.lld; do
-          sudo ln -sf $tool-20 /usr/bin/$tool
+          sudo ln -sf $tool-19 /usr/bin/$tool
           $tool --version
         done
-    - name: 'Windows: Install clang v20.1.3 from GitHub'
+    - name: 'Windows: Install clang v19.1.3 from GitHub'
       if: runner.os == 'Windows'
       shell: bash
       run: |
         set -eux
         cd ..
         curl -fL --retry 3 --max-time 300 -o clang.exe \
-          https://github.com/llvm/llvm-project/releases/download/llvmorg-20.1.3/LLVM-20.1.3-win64.exe
+          https://github.com/llvm/llvm-project/releases/download/llvmorg-19.1.3/LLVM-19.1.3-win64.exe
         ./clang.exe //S # double-slash for bash
         rm clang.exe
         # C:\Program Files\LLVM\bin should already be in PATH

.github/workflows/main.yml

@@ -14,7 +14,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  LLVM_VERSION: a905655f
+  LLVM_VERSION: 19.1.7
 
 jobs:
   build-native: