* cs-tokenizer.cs (consume_identifier): Treat 'partial' as a
keyword in 'partial enum' too.
* cs-parser.jay (enum_declaration): Add CS0267 check ('partial enum'
is not allowed).
Report from Kamil Skalski <nazgul@omega.pl>.
Fix #74309.
* rootcontext.cs (ResolveTree): The 'root.Interfaces' list can
have partial containers too.
In tests:
* test-359.cs: New test from #74309.
In errors:
* cs0267.cs: New. Mentioned in passing in #74309.
svn path=/trunk/mcs/; revision=42459
