Build the lldb asan tests with the system compiler

Author: adrian-prantl

zorg/jenkins/jobs/jobs/lldb-cmake-sanitized

@@ -103,11 +103,14 @@ pipeline {
                     # Running too many asanified threads is too stressful for the kernel and we get >90% system time.
                     export MAX_PARALLEL_TESTS=$(sysctl hw.physicalcpu |awk '{print int(($2+1)/2)}')
 
+                    # Using the system compiler to compile the LLDB tests. By default macOS does
+                    # not allow loading the ASAN runtime into system binaries.
                     python3 llvm-zorg/zorg/jenkins/monorepo_build.py lldb-cmake-sanitized build \
                       --assertions \
                       --projects="clang;lld;lldb"  \
                       --runtimes="libcxx;libcxxabi;libunwind" \
-                      --cmake-type=Release
+                      --cmake-type=Release \
+                      --lldb-test-compiler=$(xcrun -find clang)
                     '''
                     script {
                         def LLDB = new org.swift.LLDB()