Smart (in the usual understanding of smart), or good programmers (in the "can invert a binary tree on a whiteboard" sense)? These are two measures that are basically orthogonal.
Is there any evidence of that? Google selects people based on entirely different criteria, and promotes them for moving a button in Gmail from an inconvenient location to an even less convenient one.
Might depend on your definition of "intelligent" though. I've met quite a few, too, including friends and relatives. Sure, they better than average programmers, but general intelligence seems to be the same as in your general college educated population. Otherwise we'd be arguing that Damore (or, say, Altheide, if one has ideological preference for one or the other) are also "very intelligent".
I think you may be equating "good enough at programming to get hired by Google" with "generally intelligent". My point is that these are entirely different things.