SF2: Pinning pan to its range.
SF2: Pinning pan to its range.

Out-of-range values (seen in a real-world SF2) lead to NaNs that stopped the
sound from playing.

UIKit0/SFZero,altalogix/SFZero,stevefolta/SFZero,stevefolta/SFZero,altalogix/SFZero,UIKit0/SFZero,UIKit0/SFZero,stevefolta/SFZero