This has been done using the following commands
find libcxx/test -type f -exec perl -pi -e 's|^([^/]+?)((?<!::)ptrdiff_t)|\1std::\2|' \{} \; find libcxx/test -type f -exec perl -pi -e 's|^([^/]+?)((?<!::)max_align_t)|\1std::\2|' \{} \;
The std module doesn't export declarations in the global namespaace.,
This is a preparation for that module.