Clarify namespace name after moving to initializer.cpp

Author: ashfordium

clang/test/Analysis/initializer.cpp

@@ -445,7 +445,7 @@ void nested_aggregates() {
 }
 } // namespace newexpr_init_list_initialization
 
-namespace initializer_list_arg {
+namespace placement_new_initializer_list_arg {
 struct S {
   int x;
 };
@@ -470,7 +470,7 @@ void initialize_non_zeroth_argument_pointers(S *arr[2]) {
   arr[1] = new (arr[1]) S{1};
   clang_analyzer_eval(1 == arr[1]->x); // expected-warning{{TRUE}}
 }
-} // namespace initializer_list_arg
+} // namespace placement_new_initializer_list_arg
 
 namespace CXX17_transparent_init_list_exprs {
 class A {};