Sebastian Holtermann authored Sep 13, 2017 and Brad King committed Sep 13, 2017

Target dependencies of the origin target were mistakenly forwarded to
the _autogen target as *file* dependencies.  This patch introduces
proper distinction between *target* and *file* dependencies of the
_autogen target.

This patch also changes when PRE_BUILD is used for AUTOGEN in the Visual
Studio generator. Formerly PRE_BUILD was disabled when the origin target
depended on *any* other target. Now PRE_BUILD is only disabled if a
dependency of the _autogen target to an additional *file* is detected.

Fixes: #17278, #17205