ART: Dual mapping of JIT code pages

Add support for a two mappings of JIT code pages. One mapping is used
for executing code, the other for updating it. The latter mapping is
never executable.

Fallback to the existing regime when the required support is missing.

No longer allocate mappings for JIT code when cache exists only for
profiling purposes.

Bug: 66095511
Bug: 111199492
Test: art/test.py --host
Test: art/test.py --64 (angler - single view)
Test: art/test.py --64 (other - dual view)
Test: walleye boots

Change-Id: I9920534c81cbf16f375f1dd554d5952716bf3253