Pushed all these changes to guix master, except for:

0009-gnu-glib-Make-some-cosmetic-changes.patch
0010-gnu-glib-Update-to-2.64.3.patch
0011-gnu-glib-Update-synopsis-and-description.patch
0012-gnu-glib-with-documentation-Make-some-cosmetic-chang.patch
0013-gnu-glib-with-documentation-Fix-documentation.patch
0023-gnu-openjpeg-Enable-documentation.patch
0024-gnu-openjpeg-Enable-some-features.patch
0026-gnu-cairo-Make-some-cosmetic-changes.patch
0027-gnu-cairo-Change-build-system.patch
0028-gnu-cairo-Move-documentation-to-separate-output.patch
0029-gnu-cairo-Enable-some-features.patch
0030-gnu-cairo-Update-synopsis-description-and-license.patch
*-gnu-pixman-Update-synopsis-and-description.patch

Mostly because these did not apply to master cleanly, and I've only tested the
set that did apply cleanly.

Note: first uninvolved past commit on guix master is now
commit af1225a3663e73458bf8941d8373c68f9ad6bae2.