Use userfaultfd in COPY mode even when minor-fault available

Private anonymous is preferred over shmem due to performance as well as
accounting issues with the latter. Therefore use COPY ioctl.

Test: art/test/testrunner/testrunner.py
Bug: 263341475
Change-Id: I673da4fe5897416302ae0cfbecca4a429e55c65f
1 file changed