Interpreter intrinsics

First of several intrinsic CLs.  This one provides the basic
mechanism plus a handful of the most simple examples.  Note that
Intrinsic support is limited to Mterp both to keep the switch
interpreter as a pure reference, and to avoid mixing debugging
and intrinsics.

Bug: 30933338

Test: ART_TEST_INTERPRETER m test-art-host
Test: Note: existing 082-inline-execute, 123-inline-execute2
Test:   cover intrinsics enabled by this CL.

Change-Id: I9d79e23a84bf00cadb54e1db52d8ed193bbf8887