Avoid sketchy pointer stuff in read_pulse_waveform
Avoid sketchy pointer stuff in read_pulse_waveform

It's not clear to me that the standard requires keeping the bit pattern for unsigned to signed but it seems to with gcc.

BBN-Q/libx6,BBN-Q/libx6,BBN-Q/libx6,BBN-Q/libx6,BBN-Q/libx6