message: Add flags to tell compiler not to default to builtin malloc.
  This makes sure that all places use tcmalloc.
diff: @@ -53,9 +53,10 @@ set(CMAKE_BUILD_FILES_DIRECTORY ${dir})
  set(CMAKE_BUILD_DIRECTORY ${dir})
  # C++
  -set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MY_CXX_WARNING_FLAGS}")
  -set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0 -g ${MY_CXX_WARNING_FLAGS}")
  -set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -DNDEBUG ${MY_CXX_WARNING_FLAGS}")
  +set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-free ${MY_CXX_WARNING_FLAGS}")
  +set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-free -O0 -g ${MY_CXX_WARNING_FLAGS}")
  +set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-free -O3 -DNDEBUG ${MY_CXX_WARNING_FLAGS}")
  +
  # Compiler-specific C++11 activation.
  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel")
  execute_process(
  