ART: X86: GenLongArith should handle overlapped VRs

ART: X86: GenLongArith should handle overlapped VRs

In a case, when src and dest VRs are overlapped when we called
GenLongArith it may cause the incorrect use of regs.

The solution is to map src to an physical reg and work with this
reg instead of mem.

Renamed BadOverlap() to PartiallyIntersects() for consistency.

Change-Id: Ia3fc7f741f0a92556e1b2a1b084506662ef04c9d
Signed-off-by: Katkov, Serguei I <serguei.i.katkov@intel.com>
Signed-off-by: Alexei Zavjalov <alexei.zavjalov@intel.com>