[Bug target/58269] [4.9 Regression] ICE when building libobjc on x86_64-apple-darwin* after revision 201915

[mikestump at comcast dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58269

--- Comment #18 from Mike Stump <mikestump at comcast dot net> ---
On Sep 6, 2013, at 8:43 AM, howarth at nitro dot med.uc.edu
<gcc-bugzilla@gcc.gnu.org> wrote:
>        * i386.c (ix86_hard_regno_mode_ok): AVX modes are valid only when       
>        AVX is enabled.

llvm has:

  // The first 8 512-bit vector arguments are passed in ZMM registers.
  CCIfNotVarArg<CCIfType<[v16i32, v8i64, v16f32, v8f64],
            CCIfSubtarget<"hasAVX512()",
            CCAssignToReg<[ZMM0, ZMM1, ZMM2, ZMM3, ZMM4, ZMM5, ZMM6, ZMM7]>>>>,

just after the sse registers…  conceptually, I wonder if gcc is missing that.