Hide some internal symbols for memory resource.

llvm-svn: 275089
diff --git a/libcxx/src/experimental/memory_resource.cpp b/libcxx/src/experimental/memory_resource.cpp
index ff0fbb6..c01eb08 100644
--- a/libcxx/src/experimental/memory_resource.cpp
+++ b/libcxx/src/experimental/memory_resource.cpp
@@ -61,6 +61,8 @@
     { return &__other == this; }
 };
 
+namespace {
+
 union ResourceInitHelper {
   struct {
     __new_delete_memory_resource_imp new_delete_res;
@@ -74,6 +76,9 @@
 // Only in C++11 is "init_priority" needed to ensure initialization order.
 ResourceInitHelper res_init __attribute__((init_priority (101)));
 
+} // end namespace
+
+
 memory_resource * new_delete_resource() _NOEXCEPT {
     return &res_init.resources.new_delete_res;
 }