vkd3d-shader/d3dbc: Normalise I/O register write masks when not disassembling.

Sometimes SM1-3 shaders contain write masks that exceed the
signature element masks. That happens because SM1-3 shaders do not
have a concept of signature and signature masks, and OTOH aren't
always able to express any given write mask.

In VSIR we don't want to deal with I/O register masks exceeding the
corresponding signature element mask or usage mask, because, for
instance, for higher shader models it can complicate dealing with
DCL_INDEX_RANGE. In order to have uniform rules for all shader
models we normalise masks coming from SM1-3 shaders.

We don't do that normalisation when disassembling, in order to
preserve the expected output.

libs/vkd3d-shader/vkd3d_shader_private.h

@@ -1411,6 +1411,7 @@ enum vsir_control_flow_type
 
 enum vsir_normalisation_level
 {
+    VSIR_NORMALISED_SM1,
     VSIR_NORMALISED_SM4,
     VSIR_NORMALISED_HULL_CONTROL_POINT_IO,
     VSIR_NORMALISED_SM6,