Since this is already the top hit on Google, we should start a list here. I’ll make this answer a community wiki. By the way, I’m pulling these from the device’s user agent string. Browser version is iOS version dependent, NOT device dependent. But when a phone doesn’t support higher iOS versions it is listed:
3.2.2 - Mobile Safari 4.0.4
4.3.3 - Mobile Safari 5.02 - iPhone 3g
5.0 - Mobile Safari 5.1
5.1 - Mobile Safari 5.1
6.0 - Mobile Safari 6.0 - iPhone 3gs
7.1 - Mobile Safari 7.1 - iPhone 4
8.3 - Mobile Safari 8.0
9.2.1 - Mobile Safari 9.0 - iPhone 4s
10.3.4 - Mobile Safari 10.0 - iPhone 5
11.2.5 - Mobile Safari 11.0
12.1.4 - Mobile Safari 12.0
12.4.4 - Mobile Safari 12.1 - iPhone 5S, 6
13.0 - Mobile Safari 13.0
[...] - [...]
15.2 - Mobile Safari 15.2