[Place] Fix y_range Calculation for Placement

[amin1377]

y_range determines the range on the y-axis (in the compressed grid) to search for a compatible location. Within this search range, a compatible location is chosen randomly by generating a random number (dy) and adding it to search_range.ymin. rng.irand is used to generate this number, and its documentation (Link) indicates that the range is inclusive. Therefore, I believe we should pass y_range to this function, not y_range - 1. This is particularly problematic for IO blocks when the chosen x is located in the middle of the device, where y_range would be 1, resulting in dy always being zero and preventing the changing of IO block rows.

[vaughnbetz]

I think this is closed since range-1 is the right value, correct?
I think it would be good to add doxygen comments to the vtr random number generator and build it into the vtrUtil docs on the web.
@amin1377

[amin1377]

Yes, that's correct. upper_bound is used to find the upper end of the range, and it returns the first element that is greater than the specified value.

Sure, I'll add the documentation.