Optimized BFREV opcode in dxbc_debug
Optimized BFREV opcode in dxbc_debug

Main goal was to fix undefined behaviour, but it's also 50x faster...

cppcheck:
[renderdoc/driver/shaders/dxbc/dxbc_debug.cpp:1163]: (error) Shifting signed 32-bit value by 31 bits is undefined behaviour

Zorro666/renderdoc,michaelrgb/renderdoc,cgmb/renderdoc,Zorro666/renderdoc,googlestadia/renderdoc,googlestadia/renderdoc,etnlGD/renderdoc,baldurk/renderdoc,etnlGD/renderdoc,TurtleRockStudios/renderdoc_public,googlestadia/renderdoc,michaelrgb/renderdoc,Zorro666/renderdoc,michaelrgb/renderdoc,TurtleRockStudios/renderdoc_public,michaelrgb/renderdoc,Zorro666/renderdoc,baldurk/renderdoc,michaelrgb/renderdoc,googlestadia/renderdoc,cgmb/renderdoc,TurtleRockStudios/renderdoc_public,cgmb/renderdoc,TurtleRockStudios/renderdoc_public,TurtleRockStudios/renderdoc_public,etnlGD/renderdoc,TurtleRockStudios/renderdoc_public,googlestadia/renderdoc,etnlGD/renderdoc,etnlGD/renderdoc,googlestadia/renderdoc,Zorro666/renderdoc,cgmb/renderdoc,cgmb/renderdoc,Zorro666/renderdoc,baldurk/renderdoc,baldurk/renderdoc,baldurk/renderdoc,etnlGD/renderdoc,baldurk/renderdoc