scanner: fix pairing of error quarks with registered enums

_uscore_type_names maps from the c_symbol_prefix, which has the
global ns prefix removed, so we need to split the function symbol
before the lookup. Previously it worked because it used the heuristics
for unregistered enums (and failed for GDBusError, which has two
uppercase letters in succession)

https://bugzilla.gnome.org/show_bug.cgi?id=669350
scanner: complete the enum-to-error-quark fix

Turns out that the problem was not only in the wrong matching
to GType enums, but also that the non-GType heuristics used
to_underscores instead of to_underscores_noprefix, turning DBusError
into D_Bus_Error instead of DBus_Error.
Complete with various tests.

https://bugzilla.gnome.org/show_bug.cgi?id=669350
Update glib annotations from git
Release 1.33.3
Revert scanner fix in 64f3832

This is incorrect -- the type name that's passed to the function
should contain a prefix. This fixes error domains for GLib errors.
Don't revert doc changes or test additions.
fix GIArgument being exported as _Argument in .gir

https://bugzilla.gnome.org/show_bug.cgi?id=635128
scanner: Don't use an O(N) lookup when we already have a hashmap

This is a general code cleanup.
scanner: Remove properties

We don't need a basic getter for a private field - this isn't Java.
Fix build
tests: Add SLetter

This test case has a single-letter symbol prefix, which triggers
edge cases in the difference between prefix handling.

See https://bugzilla.gnome.org/show_bug.cgi?id=637025
tests: Add GSpawnError-alike to SLetter

See https://bugzilla.gnome.org/show_bug.cgi?id=637025 for motivation.
Add missing SLetter expected gir
Maintransfomer: fix again paring error domains with unregistered enums

Previous fix was wrong, as it called to_underscores_noprefix on a
prefixed type name. The actual fix is to call the transformer to
do the prefix / type_name split, and turn the latter to underscores.
Test case included.

https://bugzilla.gnome.org/show_bug.cgi?id=634202
tests: Ignore SLetter generated gir.

https://bugzilla.gnome.org/show_bug.cgi?id=656445
giscanner: Fix pointer parsing.

They were parsed in wrong order resulting in having wrong pointer
being const. For example - g_settings_list_schemas return type is
normally 'const gchar *const *', but parsing result was
'const gchar ** const'.

This was unnoticed, because pointer constness information is rather
not used by gobject-introspection now.

https://bugzilla.gnome.org/show_bug.cgi?id=656445
scanner: Turn dead code into assertion

https://bugzilla.gnome.org/show_bug.cgi?id=656445
giscanner: Write detailed information in "type" tag's "c:type" attribute.

That is - write also type qualifiers (const and volatile here). Update
existing tests and add a new struct to regress.h having members with
type qualifiers.

https://bugzilla.gnome.org/show_bug.cgi?id=656445
scanner: Ensure "complete_ctype" patch doesn't throw an exception for anonymous unions

The previous patch introduced a regression where we would crash on
encountering an anonymous union.  Work around this by just writing out
'gpointer' in this case, and add a regression test.
scanner: support stability tag

https://bugzilla.gnome.org/show_bug.cgi?id=679160
Update glib annotations from git