i386.md ("sse4_1_blendvpd"): Require "z" class XMM register for operand[3].

i386.md ("sse4_1_blendvpd"): Require "z" class XMM register for operand[3].

        * config/i386/i386.md ("sse4_1_blendvpd"): Require "z" class XMM
        register for operand[3].  Adjust asm template.
        ("sse4_1_blendvpd"): Ditto.
        ("sse4_1_pblendvb"): Ditto.
        * config/i386/i386.c (ix86_expand_sse_4_operands_builtin): Call
        safe_vector_operand() if input operand is VECTOR_MODE_P operand. Do not
        force operands[3] into xmm0 register for variable blend instructions.
        (ix86_expand_sse_pcmpestr): Do not check operands for
        "register_operand", when insn operand predicate is "register_operand".
        (ix86_expand_sse_pcmpistr): Ditto.

From-SVN: r125280