Someone else must have received this message while (or after) converting an iOS project to Swift 3, yet when I do a Google search, I get no relevant results.
Anyway,
Looks like a bug in the Swift compiler:
https://bugs.swift.org/browse/SR-2921
Currently, I'm seeing this with Xcode 8.1 and 8.2 beta 1.
In your case, the warning should identify the source file, but not the line - as you stated. You will have to hunt around for calls to functions with Any
parameters.
Good new is that it appears fixed in an upcoming Swift toolchain.
I believe this is fixed in Xcode 8.3 beta 1 (but have not confirmed)