add static_cast where missing (#76756)
add static_cast where missing (#76756)

Summary:
X-link: https://github.com/pytorch/pytorch/pull/76756

Add `static_cast` to implicit int -> float conversions.

Reviewed By: yfeldblum

Differential Revision: D35857046

fbshipit-source-id: 0560125fed19e74eff85e22cfab971893515f4dc

facebook/wangle,facebook/wangle,facebook/wangle