[optimizing] Add RIP support for x86_64

Support a constant area addressed using RIP on x86_64. Use it for FP
operations to avoid loading constants into a CPU register and moving
to a XMM register.

Change-Id: I58421759ef2a8475538876c20e696ec787015a72
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>
5 files changed