dillon1000/react

Prevent performance regression in DEV due to warning arguments (#7461)

* Prevent internal performance regression

This only affects Facebook website, not open source version of React.

On the Facebook website, we don't have a transform for warnings and invariants.
Therefore, expensive arguments will be calculated even if the warning doesn't fire.
This fixes a few cases where that calculation might be more expensive than usually.

In my testing, this brings down average row click time in Power Editor from ~300ms to ~220ms in __DEV__ (vs ~40ms in prod).

* Put warning() that shows up in profile behind condition