[DirectX] Validator is complaining about Flags must match usage.

[farzonl]

error: Flags must match usage.
66 cases

There are three cases:

1. Flags declared=524336, actual=557104
   32 cases
2. Flags declared=0, actual=32768
   20 cases
3. Flags declared=48, actual=32816
   14 cases

All three cases are caused by bit 0x8000 not being set when it should be set.
This bit corresponds to the Max64UAVs (64 UAV slots) shader flag.