Sebastian Holtermann authored Jun 06, 2019 and Brad King committed Jun 06, 2019

When Autogen searches the header for a source files in a target,
the expanded real path is used and not the (possibly symbolic) original path
of the source file.  If the source file path contains symbolic links, then the
correct `cmSourceFile` instance of the header won't be found, but a new one
will be generated.  This way all header source file properties get lost, which
is problematic especially for the `SKIP_AUTOMOC/UIC/GEN` properties.

This patch changes the header detection in Autogen to use the original source
file path instead of the expanded real source file path.

Fixes: #19346