Runtimes: enable build of SwiftOnoneSupport on Apple platforms.

Addresses rdar://145066924

Author: edymtt

Runtimes/Core/cmake/caches/Vendors/Apple/apple-common.cmake

@@ -13,8 +13,6 @@ set(SwiftCore_ENABLE_RUNTIME_FUNCTION_COUNTERS ON CACHE BOOL "")
 set(SwiftCore_ENABLE_BACKDEPLOYMENT_SUPPORT ON CACHE BOOL "")
 set(SwiftCore_ENABLE_FILESYSTEM_SUPPORT ON CACHE BOOL "")
 
-set(SwiftCore_ENABLE_ONONESUPPORT OFF CACHE BOOL "")
-
 set(SwiftCore_INSTALL_NESTED_SUBDIR OFF CACHE BOOL "")
 
 set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -g -DNDEBUG" CACHE STRING "")