message: Clamp to _almost_ zero in float_to_srgb8(), fixes
  Correctly clamping avoids a segfault when accessing LUT.
diff: @@ -4394,10 +4394,11 @@ float_to_srgb8(float inval)
  0x70940818, 0x74a007bd, 0x787d076c, 0x7c330723,
  };
  + static const uniform unsigned int near_zero = 0x39000000;
  static const uniform unsigned int almost_one = 0x3f7fffff;
  // Clamp to [2^(-13), 1-eps]; these two values map to 0 and 1, respectively.
  - inval = max(inval, 0.0f);
  + inval = max(inval, floatbits(near_zero));
  inval = min(inval, floatbits(almost_one));
  // Do the table lookup and unpack bias, scale
  @@ -4444,10 +4445,11 @@ float_to_srgb8(uniform float inval)
  0x70940818, 0x74a007bd, 0x787d076c, 0x7c330723,
  };
  + static const uniform unsigned int near_zero = 0x39000000;
  static const uniform unsigned int almost_one = 0x3f7fffff;
  // Clamp to [2^(-13), 1-eps]; these two values map to 0 and 1, respectively.
  - inval = max(inval, 0.0f);
  + inval = max(inval, floatbits(near_zero));
  inval = min(inval, floatbits(almost_one));
  // Do the table lookup and unpack bias, scale
  