Revert "Revert "X86: Use the constant area for more operations.""

This reverts commit cf8d1bb9.

Handle the case of an intrinsic where CurrentMethod is still an input.
This will be the case when there are unresolved classes in the
hierarchy.

Add a test case to confirm that we don't crash when handling Math.abs,
which wants to add a pointer to the constant area for the bitmask to be
used to remove the sign bit.

Enhance 565-checker-condition-liveness to check for the case of deeply
nested EmitAtUseSite chains.

Change-Id: I022e8b96a32f5bf464331d0c318c56b9d0ac3c9a