build: try to disable warnings for cr.h

Author: skypjack

test/CMakeLists.txt

@@ -153,6 +153,10 @@ if(ENTT_BUILD_LIB)
     if(NOT cr_POPULATED)
         FetchContent_Populate(cr)
         set(cr_INCLUDE_DIR ${cr_SOURCE_DIR})
+
+        if(NOT MSVC)
+            set_source_files_properties(${cr_SOURCE_DIR}/cr.h PROPERTIES COMPILE_OPTIONS "-Wno-sign-conversion")
+        endif()
     endif()
 
     SETUP_LIB_SHARED_TEST(dispatcher shared)