auto merge of #10844 : huonw/rust/deriving-expn-info, r=alexcrichton

Previously something like

    struct NotEq;

    #[deriving(Eq)]
    struct Error {
        foo: NotEq
    }

would just point to the `foo` field, with no mention of the
`deriving(Eq)`. With this patch, the compiler creates a note saying "in
expansion of #[deriving(Eq)]" pointing to the Eq.

(includes some cleanup/preparation; the commit view might be nicer, to filter out the noise of the first one.)

0 files changed, 0 insertions, 0 deletions