Request for reviews (M): 7181494: cleanup avx and vectors code

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/7181494/webrev

7181494: cleanup avx and vectors code

Use shorter (non-ladder) form for XMM registers definition in x86.ad.

Do renaming (vsubF_reg --> subF_reg_reg) for mach nodes which use AVX 
(3-operands) scalar instructions to avoid confusing with vector nodes.

Add integer vectors shuffling instructions since SIMD Integer execution unit is 
separate from Float unit in SSE - there is at least one cycle penalty  for 
moving data between them. Use them in replicate integer values mach nodes.

Tested with compiler regression tests and CTW.

Thanks,
Vladimir