ci: Add nightly job to build CMake with PCH on macOS

.gitlab-ci.yml

@@ -826,6 +826,15 @@ b:macos-arm64-ninja:
     variables:
         CMAKE_CI_JOB_CONTINUOUS: "true"
 
+b:macos-arm64-pch:
+    extends:
+        - .macos_arm64_pch
+        - .cmake_build_macos
+        - .macos_arm64_tags
+        - .run_manually
+    variables:
+        CMAKE_CI_JOB_NIGHTLY: "true"
+
 t:macos-x86_64-ninja:
     extends:
         - .macos_x86_64_ninja

.gitlab/ci/configure_macos_arm64_pch.cmake

@@ -0,0 +1,7 @@
+set(CMake_BUILD_PCH "ON" CACHE BOOL "")
+
+# sccache does not forward the PCH '-Xarch_arm64 "-include/..."' flag correctly.
+set(configure_no_sccache 1)
+
+include("${CMAKE_CURRENT_LIST_DIR}/configure_macos_common.cmake")
+include("${CMAKE_CURRENT_LIST_DIR}/configure_common.cmake")

.gitlab/os-macos.yml

@@ -38,6 +38,12 @@
         CMAKE_CONFIGURATION: macos_arm64_ninja
         CTEST_NO_WARNINGS_ALLOWED: 1
 
+.macos_arm64_pch:
+    extends: .macos_arm64_ninja
+
+    variables:
+        CMAKE_CONFIGURATION: macos_arm64_pch
+
 .macos_x86_64_makefiles:
     extends: .macos_build