build(cmake): disable warnings as errors on Clang (modules)

cmake/warnings.cmake

@@ -25,6 +25,10 @@
 cmake_minimum_required(VERSION 3.15)
 
 option(${projectPrefix}WARNINGS_AS_ERRORS "Treat compiler warnings as errors" ON)
+if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND ${projectPrefix}BUILD_MODULES)
+    # Workaround <https://github.com/llvm/llvm-project/issues/54574>.
+    set(${projectPrefix}WARNINGS_AS_ERRORS "Treat compiler warnings as errors" OFF)
+endif()
 
 macro(_set_flags)
     set(MSVC_WARNINGS
@@ -71,7 +75,7 @@ macro(_set_flags)
         -Wdangling-else # warn about constructions where there may be confusion to which if statement an else branch belongs
     )
 
-    set(CLANG_WARNINGS ${GCC_COMMON_WARNINGS})
+    set(CLANG_WARNINGS ${GCC_COMMON_WARNINGS} -Wno-error=read-modules-implicitly)
 
     set(GCC_WARNINGS
         ${GCC_COMMON_WARNINGS}