Jump-to-definition to init of a C struct does not work

[ahoppen]

When doing jump to definition on the timespec initializer in the following (jump-to-definition on tv_spec), it doesn’t jump anywhere, probably because the C struct doesn’t have an initializer.

import Darwin

func test() {
  _ = timespec(tv_sec: 0, tv_nsec: 0)
}

rdar://126382075