Description
DXIL lowering of splitdouble writes the output matrices in column-major flat order while consuming the input row-major, producing transposed low/high matrices.

Steps to Reproduce
https://hlsl.godbolt.org/z/rd18nG95x

Actual Behavior
https://hlsl.godbolt.org/z/rd18nG95x, line 40 of DXIL should be:

  call void @dx.op.rawBufferStore.i32(i32 140, %dx.types.Handle %Lows_UAV_structbuf, i32 0, i32 0, i32 %5, i32 %7, i32 %9, i32 %11, i8 15, i32 4), !dbg !119