swift234

Swallow semicolons after decls when in a container.

Outside of a container, semicolons after decls are just parsed as SemiStmts.
Inside a container, though, we only allow decls...but we should still allow
trailing (delimiting?) semicolons.

If you have multiple semicolons in a row, though, that's probably a typo,
so parseDecl will now also complain (error) if it sees a semicolon where
a decl is expected.

<rdar://problem/12540877>

Swift SVN r3051