x86: implement rcpps and rcpss SSE insts

These are packed single-precision approximate reciprocal operations,
vector and scalar versions, respectively.

This code was basically developed by copying the code for
sqrtps and sqrtss. The mrcp micro-op was simplified relative to
msqrt since there are no double-precision versions of this operation.

x86: implements the simd128 ADDSUBPD instruction

This patch implements the simd128 ADDSUBPD instruction for the x86 architecture.

Tested with a simple program in assembly language which executes the
instruction. Checked that different versions of the instruction are executed
by using the execution tracing option.

Committed by: Nilay Vaish <nilay@cs.wisc.edu

x86 ISA: Implement the sse3 haddps instruction.

Shuffle the 32 bit values into position, and then add in parallel.

copyright: Change HP copyright on x86 code to be more friendly

X86: Create a common flag with a name to indicate scalar media instructions.

X86: Implement the X86 sse2 haddpd instruction

This patch implements the haddpd instruction.

It fixes the problem in the previous version (pointed out by Gabe Black)
where an incorrect result would happen if you issue the instruction
with the same argument twice, i.e. "haddpd %xmm0,%xmm0"

This instruction is used by many spec2k benchmarks.

X86: Implement the floating point media instructions.

X86: Implement the floating point media multiply instructions.

X86: Implement the floating point media subtract instructions.

X86: Implement the floating point media add instructions.

X86: Implement the media sqrt instructions.

X86: Ignore the size part of XMM/MMX operands. The instructions know what they want.

X86: Use suffixes to differentiate XMM/MMX/GPR operands.

X86: Put in stubs for x87, 64 bit and 128 bit SIMD instruction microcode.