Print message when configuring for standalone build.

llvm-svn: 243737
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 5e6aa9bdebbcce4857e119345af884efd5a234e3
diff --git a/cmake/Modules/HandleOutOfTreeLLVM.cmake b/cmake/Modules/HandleOutOfTreeLLVM.cmake
index 1cd3cd7..bf629a9 100644
--- a/cmake/Modules/HandleOutOfTreeLLVM.cmake
+++ b/cmake/Modules/HandleOutOfTreeLLVM.cmake
@@ -58,6 +58,7 @@
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   set(LIBCXX_BUILT_STANDALONE 1)
+  message(STATUS "Configuring for standalone build.")
 
   find_llvm_parts()