Fix Bug#1180494 "Concurrent CMake build does not work properly"

cmake/BuildLibOBJC.cmake

@@ -34,7 +34,7 @@ macro(libobjc_build)
     separate_arguments(extra_ldflags)
     if (NOT (${PROJECT_BINARY_DIR} STREQUAL ${PROJECT_SOURCE_DIR}))
         add_custom_command(OUTPUT ${PROJECT_BINARY_DIR}/third_party/libobjc
-            COMMAND mkdir -p ${PROJECT_BINARY_DIR}/third_party/libobjc
+            COMMAND ${CMAKE_COMMAND} -E make_directory "${PROJECT_BINARY_DIR}/third_party/libobjc"
             COMMAND cp -r ${PROJECT_SOURCE_DIR}/third_party/libobjc/*
                 ${PROJECT_BINARY_DIR}/third_party/libobjc
         )

cmake/luajit.cmake

@@ -160,7 +160,7 @@ macro(luajit_build)
         )
     else()
         add_custom_command(OUTPUT ${PROJECT_BINARY_DIR}/third_party/luajit
-            COMMAND mkdir ${PROJECT_BINARY_DIR}/third_party/luajit
+            COMMAND ${CMAKE_COMMAND} -E make_directory "${PROJECT_BINARY_DIR}/third_party/luajit"
         )
         add_custom_command(OUTPUT ${PROJECT_BINARY_DIR}/third_party/luajit/src/libluajit.a
             WORKING_DIRECTORY ${PROJECT_BINARY_DIR}/third_party/luajit