Fix compiler program name for apple-clang

Try to fix CI build with CXX_MODULES

Author: ClausKlein

CMakeLists.txt

@@ -60,6 +60,8 @@ message(
     "cmake is: ${CMAKE_VERSION} modules scan :  ${CMAKE_CXX_SCAN_FOR_MODULES}"
 )
 
+# gersemi: off
+
 if(CMAKE_CXX_SCAN_FOR_MODULES)
     add_library(beman.scope)
     target_sources(
@@ -126,7 +128,8 @@ if(BEMAN_SCOPE_INSTALL_CONFIG_FILE_PACKAGE)
         EXPORT beman.scope-targets
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/beman.scope
         NAMESPACE beman::
-        CXX_MODULES_DIRECTORY cxx-modules
+        CXX_MODULES_DIRECTORY
+        cxx-modules
         COMPONENT beman.scope
     )
 endif()

cmake/appleclang-toolchain.cmake

@@ -16,8 +16,8 @@
 
 include_guard(GLOBAL)
 
-set(CMAKE_C_COMPILER clang)
-set(CMAKE_CXX_COMPILER clang++)
+set(CMAKE_C_COMPILER gcc)
+set(CMAKE_CXX_COMPILER g++)
 
 if(BEMAN_BUILDSYS_SANITIZER STREQUAL "MaxSan")
     set(SANITIZER_FLAGS