pixman

• demos require both gtk and openmp support
• tests require openmp support (on Void?)
• stacksize patch for use with musl to prevent segfaults with librsvg: LDFLAGS="-Wl,-z,stack-size=2097152"

References

• https://git.adelielinux.org/adelie/packages/-/blob/current/user/pixman/stacksize-reduction.patch