* tests/unistr/test-pcpy.h: New file, based on tests/unistr/test-cpy.h.
* tests/unistr/test-u8-pcpy.c: New file, based on
tests/unistr/test-u8-cpy.c.
* tests/unistr/test-u16-pcpy.c: New file, based on
tests/unistr/test-u16-cpy.c.
* tests/unistr/test-u32-pcpy.c: New file, based on
tests/unistr/test-u32-cpy.c.
* modules/unistr/u8-pcpy-tests: New file, based on
modules/unistr/u8-cpy-tests.
* modules/unistr/u16-pcpy-tests: New file, based on
modules/unistr/u16-cpy-tests.
* modules/unistr/u32-pcpy-tests: New file, based on
modules/unistr/u32-cpy-tests.