literal: promote `as_X` from annotation

Signed-off-by: Jean Privat <jean@pryen.org>
parser_nodes: promote `get_annotation` and `AAnnotation::name` from `annotation`

Signed-off-by: Jean Privat <jean@pryen.org>
parser: promote `collect_X` from `parser_util`

Signed-off-by: Jean Privat <jean@pryen.org>
toolcontext: enable blacklisting of warnings by source-file.

Signed-off-by: Jean Privat <jean@pryen.org>
frontend: new phase and annotation `no_warning` to disable warning per module

Signed-off-by: Jean Privat <jean@pryen.org>
parser: add `no_warning` in generated files to disable some warnings

Signed-off-by: Jean Privat <jean@pryen.org>