bitmask: Fix intersection code
bitmask: Fix intersection code

With the fix in 77912a65e2aa6eb9cfee994fa93bbfbc6b9f8538, another bug
got visible: booleans are 32 bits, so if the intersection between the 2
bitmasks happened in higher bits, the return value would be truncated to
FALSE.

This actually made slider handles disappear, so it was pretty visible.

Adamovskiy/gtk,davidgumberg/gtk,Adamovskiy/gtk,davidgumberg/gtk,jessevdk/gtk,jigpu/gtk,ahodesuka/gtk,ebassi/gtk,jigpu/gtk,Lyude/gtk-,Sidnioulz/SandboxGtk,Distrotech/gtk2,chergert/gtk,ebassi/gtk,jadahl/gtk,Adamovskiy/gtk,Distrotech/gtk2,msteinert/gtk,jadahl/gtk,grubersjoe/adwaita,davidgumberg/gtk,bratsche/gtk-,Sidnioulz/SandboxGtk,jadahl/gtk,Lyude/gtk-,jessevdk/gtk,ahodesuka/gtk,msteinert/gtk,davidt/gtk,bratsche/gtk-,Sidnioulz/SandboxGtk,jadahl/gtk,davidt/gtk,chergert/gtk,Adamovskiy/gtk,chergert/gtk,Lyude/gtk-,grubersjoe/adwaita,bratsche/gtk-,chergert/gtk,jadahl/gtk,ahodesuka/gtk,jessevdk/gtk,Adamovskiy/gtk,jadahl/gtk,bratsche/gtk-,Sidnioulz/SandboxGtk,ahodesuka/gtk,msteinert/gtk,alexlarsson/gtk,jessevdk/gtk,bratsche/gtk-,davidt/gtk,msteinert/gtk,Adamovskiy/gtk,jigpu/gtk,davidgumberg/gtk,Lyude/gtk-,Lyude/gtk-,Lyude/gtk-,alexlarsson/gtk,davidgumberg/gtk,jessevdk/gtk,Distrotech/gtk2,alexlarsson/gtk,msteinert/gtk,ebassi/gtk,Adamovskiy/gtk,alexlarsson/gtk,davidt/gtk,ahodesuka/gtk,chergert/gtk,alexlarsson/gtk,chergert/gtk,chergert/gtk,jigpu/gtk,ebassi/gtk,Distrotech/gtk2,ahodesuka/gtk,jigpu/gtk,alexlarsson/gtk,davidt/gtk,grubersjoe/adwaita,Distrotech/gtk2,davidgumberg/gtk,grubersjoe/adwaita,Lyude/gtk-,davidgumberg/gtk,jigpu/gtk,grubersjoe/adwaita,ebassi/gtk,Adamovskiy/gtk,Sidnioulz/SandboxGtk,jadahl/gtk,ahodesuka/gtk,ebassi/gtk,alexlarsson/gtk,alexlarsson/gtk,grubersjoe/adwaita,Distrotech/gtk2,Lyude/gtk-,bratsche/gtk-,msteinert/gtk,davidgumberg/gtk,jessevdk/gtk,grubersjoe/adwaita,Sidnioulz/SandboxGtk,jessevdk/gtk,jigpu/gtk,ahodesuka/gtk,jigpu/gtk,grubersjoe/adwaita,chergert/gtk,davidt/gtk,jadahl/gtk