profiles: Add a gdk-pixbuf-loaders-cache-file hook.

This paves the way toward properly fixing https://issues.guix.gnu.org/50957.

* guix/profiles.scm (gdk-pixbuf-loaders-cache-file): Add procedure...
(%default-profile-hooks): ... and register it as a profile hook.
* guix/status.scm (hook-message): Register it here too.

build: glib-or-gtk: Generate the gdk-pixbuf-loaders cache file in a phase.

Adding a profile hook to do so covers most use cases, but it is still
necessary to have the gdk-pixbuf loaders cache file computed at build time, as
software may expect to find loaders support at that time.

* guix/build/glib-or-gtk-build-system.scm: Delete trailing #t.
(%gdk-pixbuf-loaders-cache-file-prefix): New variable.
(generate-gdk-pixbuf-loaders-cache): New procedure.
(generate-gdk-pixbuf-loaders-cache-file): Add procedure...
(%standard-phases): ... and register it as a build phase.

gnu: gtk: Add the generate-gdk-pixbuf-loaders-cache-file phase.

* gnu/packages/gtk.scm (gtk+)[arguments]: Import the (guix build
glib-or-gtk-build-system) module and put it in scope.
[phases]{generate-gdk-pixbuf-loaders-cache-file}: New phase.
(gtk): Likewise.

gnu: ungoogled-chromium: Use the new lld-as-ld-wrapper.

* gnu/packages/chromium.scm (make-lld-wrapper): Delete procedure.
(ungoogled-chromium)[native-inputs]: Replace its use by lld-as-ld-wrapper.

gnu: llvm: Add make-lld-wrapper, lld-wrapper and lld-as-ld-wrapper.

* gnu/packages/llvm.scm (make-lld-wrapper): New procedure.
(lld-wrapper, lld-as-ld-wrapper): New variables.

gnu: python-flit: Update to 3.3.0.

* gnu/packages/python-xyz.scm (python-flit): Update to 3.3.0.

gnu: webkitgtk: Add a debug output.

* gnu/packages/webkit.scm[outputs]: Add a debug output.

gnu: pulseaudio: Add doxygen to fix build.

* gnu/packages/pulseaudio.scm (pulseaudio)[native-inputs]: Add doxygen.

gnu: webkitgtk: Use libsoup 3 and build with GCC.

Clang is not needed when building with libsoup 3.

* gnu/packages/webkit.scm (webkitgtk): Delete trailing #t.
[configure-flags]: Remove -DUSE_SOUP2.
[phases]{prepare-build-environment}: Remove phase.
[native-inputs]: Remove clang.

gnu: libsoup: Update to 3.0.1.

* gnu/packages/gnome.scm (libsoup-minimal): Update to 3.0.1.
[modules]: Delete argument.
[phases]{adjust-tests}: Re-enable ssl-test.
[native-inputs]: Add gnutls, for tests.  Move nghttp2:lib to...
[propagated-inputs]: ... here.  Add nghttp2, which contains the pkg-config
files.
(vala-0.52): Add older variant.
(libsoup-minimal-2): New variable.
(rest)[propagated-inputs]: Use libsoup-minimal-2.
(geoclue)[inputs]: Likewise.
* gnu/packages/inkscape.scm (inkscape)[inputs]: Likewise.

gnu: libsoup: Reverse inheritance relationship with libsoup-minimal.

Because starting small and adding more on top is easier maintenance-wise than
the reverse.

* gnu/packages/gnome.scm (libsoup-minimal): New variable, made by stripping
all doc-related output, phases and inputs from libsoup.
[outputs]: Remove doc output.
[configure-flags]: Set gtk_doc option to false.
[phases]{patch-docbook-xml, move-doc}: Remove phases.
[native-inputs]{docbook-xml-4.1.2, gtk-doc}: Remove inputs.
(libsoup): Inherit from the above.
[outputs]: Re-add "doc" output.
[configure-flags]: Set gtk_doc option to true.
[phases]{patch-docbook-xml, move-doc}: Re-add phases.
[native-inputs]{docbook-xml-4.1.2, gtk-doc}: Re-add inputs.

gnu: vala: Update to 0.54.2.

* gnu/packages/gnome.scm (vala): Update to 0.54.2.  Delete trailing #t.

gnu: glib-networking: Update to 2.70.rc.

This resolves test suite errors following the upgrade to glib 2.70.

* gnu/packages/gnome.scm (glib-networking): Update to 2.70.rc.

gnu: glib: Update to 2.70, specify a bindir prefix and hide package.

* gnu/packages/glib.scm (glib): Update to 2.70.  Remove trailing #t.
[outputs]: Add a debug output.
[configure-flags]: Specify --bindir and disable manpage generation.
[phases]{disable-failing-tests}: Disable the flaky testfilemonitor test.
{move-static-libraries}: Use rename-file instead of link and delete.
{move-bin}: Rename to...
{patch-pkg-config-files}: ... this, and adjust the substitutions.
[native-inputs]: Remove docbook-xsl, libxml2 and libxslt.
[properties]: Re-add the hidden? property that commit 18f73d80416 had
temporarily removed.
(glib-with-documentation)[properties]: Revert to a visible package.
[native-inputs]: Add docbook-xsl and libxslt.
[configure-flags]: Delete the inherited "-Dman=false" flag.

gnu: libthai: Make datrie a normal native-input.

* gnu/packages/gtk.scm (libthai)[native-input]: Remove conditional on the
datrie input.

gnu: pango: Update to 1.48.10.

* gnu/packages/gtk.scm (pango): Update to 1.48.10.  Remove trailing #t.
[inputs]: Remove conditional on the bash-minimal input.

gnu: heimdal: Fix build.

* gnu/packages/kerberos.scm (heimdal): Remove trailing #t.
[inputs]: Add mit-krb5.  Add bash-minimal inconditionally.
[native-inputs]: Add perl inconditionally.

gnu: util-linux: Globally disable the lsns test.

Justification: the test also failed on the CI for x86_64 and caused an
evaluation to fail.

* gnu/packages/linux.scm (util-linux)[phases]{disable-lsns-test}: Disable
globally.

gnu: mit-krb5: Absorb 1.19.2 graft.

* gnu/packages/kerberos.scm (mit-krb5)[replacement]: Remove.
[source]: Update to 1.19.2.
(mit-krb5-1.19.2): Delete variable.

gnu: openssl: Absorb 1.1.1l graft.

* gnu/packages/tls.scm (openssl)[replacement]: Remove.
[source]: Update to 1.1.1l.  Fix indentation.
* gnu/packages/tls.scm (openssl-1.1.1l): Delete variable.