sm6_metadata_get_float_value() already calls sm6_value_is_constant()
itself, and some compilers (rightly) emit a warning that the conversion
of UINT_MAX to float changes the value.
And other related identifiers similarly.
Currently we use VALUE_TYPE_ICB to indicate a raw chunk of data
(which can be used as an immediate constant buffer, but also for
initializing an indexable temporary) and VALUE_TYPE_REG with
register type VKD3DSPR_IMMCONSTBUFFER to indicate an actual ICB
register.
Since we are now switching to represent the register type directly
in the SM6 value, it seems sensible to use VALUE_TYPE_ICB for an
ICB register. Indeed, since what we're currently describing with
VALUE_TYPE_ICB is not necessarily related to an ICB register, it
makes sense to use a more general name, which is therefore being
introduced with this commit.
VALUE_TYPE_UNDEFINED means that a value is explicitly undefined,
equivalently to what was first represented with is_undefined.
VALUE_TYPE_INVALID will be introduced for values that arise from
invalid programs.
This effectively moves "null_event_cond" from struct d3d12_fence and
"latch" from struct vkd3d_waiting_event together into a separate
structure, as well as storing the signalling function in struct
vkd3d_waiting_event instead of getting it from struct d3d12_device. I
think that largely makes sense on its own, but storing the signalling
function in struct vkd3d_waiting_event also allows us to more easily
implement d3d12_device_SetEventOnMultipleFenceCompletion() in a
subsequent commit.