Lagom: Allow opting into linking with mold

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/a6c6c24428
Pull-request: https://github.com/SerenityOS/serenity/pull/19321
Reviewed-by: https://github.com/trflynn89

Meta/CMake/lagom_options.cmake

@@ -11,5 +11,6 @@ serenity_option(ENABLE_FUZZERS_LIBFUZZER OFF CACHE BOOL "Build fuzzers using Cla
 serenity_option(ENABLE_FUZZERS_OSSFUZZ OFF CACHE BOOL "Build OSS-Fuzz compatible fuzzers")
 serenity_option(BUILD_LAGOM OFF CACHE BOOL "Build parts of the system targeting the host OS for fuzzing/testing")
 serenity_option(ENABLE_LAGOM_CCACHE ON CACHE BOOL "Enable ccache for Lagom builds")
+serenity_option(ENABLE_LAGOM_MOLD OFF CACHE BOOL "Enable mold for Lagom builds")
 serenity_option(ENABLE_LAGOM_LIBWEB ON CACHE BOOL "Enable compiling LibWeb for Lagom builds")
 serenity_option(ENABLE_LAGOM_LADYBIRD OFF CACHE BOOL "Enable compiling Ladybird from Lagom")

Meta/Lagom/CMakeLists.txt

@@ -124,6 +124,10 @@ if (ENABLE_UNDEFINED_SANITIZER)
     set(LINKER_FLAGS "${LINKER_FLAGS} -fsanitize=undefined")
 endif()
 
+if (ENABLE_LAGOM_MOLD)
+    add_link_options(-fuse-ld=mold)
+endif()
+
 if (ENABLE_FUZZERS)
     add_compile_options(-fno-omit-frame-pointer)
 endif()