Correct the criteria used to set shader flag 16 (UAVs at every shader stage)

Author: Icohedron

docs/DXIL.rst

@@ -536,7 +536,7 @@ Bit SM   Description
 13       Typed UAV load additional formats                                                        Use of TextureLoad or BufferLoad on a UAV with a multi-component data type. If DXIL validator version == 1.0 then this flag is set when a TextureLoad or BufferLoad is used on any UAV, regardless of its data type
 14       Comparison filtering for feature level 9                                                 Not set
 15       64 UAV slots                                                                             The presence of more than 8 UAVs. If Shader Model >= 6.6, then UAV ranges count as multiple UAVs
-16       UAVs at every shader stage                                                               The shader has UAVs and: if Shader Model >= 6.8, the shader is a vertex, hull, domain, or geometry shader; else (Shader Model < 6.8) the shader is not a compute or pixel shader
+16       UAVs at every shader stage                                                               The shader has UAVs and: if DXIL validator version >= 1.8, the shader is a vertex, hull, domain, or geometry shader; else (DXIL validator version < 1.8) the shader is not a compute or pixel shader
 17       CS4 raw and structured buffers                                                           Use of RawBuffer or StructuedBuffer in a Shader Model 4.x compute shader
 18       Raster Ordered UAVs                                                                      Global presence of a rasterizer ordered view (ROV)
 19       Wave level operations                                                                    Use of any wave or quad intrinsic: WaveIsFirstLane, WaveGetLaneIndex, WaveGetLaneCount, WaveAnyTrue, WaveAllTrue, WaveActiveAllEqual, WaveActiveBallot, WaveReadLaneAt, WaveReadLaneFirst, WaveActiveOp, WaveActiveBit, WavePrefixOp, QuadReadLaneAt, QuadOp, WaveAllBitCount, WavePrefixBitCount, WaveMatch, WaveMultiPrefixOp, WaveMultiPrefixBitCount, QuadVote