Revert "Fix regression when assigning owned expressions to unowned variables."
Revert "Fix regression when assigning owned expressions to unowned variables."

This reverts commit ba1fa0759989dcbb9046c7dfc06cce6c4aa23411.

Due to bug #736774

rvu95/vala,spidermonkdust/vala,GNOME/vala,frida/vala,spidermonkdust/vala,GNOME/vala,flobrosch/vala-fixes,flobrosch/vala-fixes,frida/vala,frida/vala,flobrosch/vala-fixes,rvu95/vala,GNOME/vala,frida/vala,spidermonkdust/vala,frida/vala,GNOME/vala,rvu95/vala