Revert "ART: Dual mapping of JIT code pages"

This reverts commit 0e314f08.

Reason for revert: Breaks test-art-host-run-test-debug-prebuild-interpreter-no-relocate-ntrace-cms-checkjni-no-image-pictest-ndebuggable-no-jvmti-cdex-fast-595-profile-saving64.

Bug: 66095511
Bug: 111199492
Change-Id: I6ca09e6c60e49647dfe6cc52708b1843c8acc89a