go/doc: steps towards collecting methods of embedded types
go/doc: steps towards collecting methods of embedded types

No visible external changes yet. The current approach is
a stop-gap approach: For methods of anonymous fields to be
seen, the anonymous field's types must be exported.

Missing: computing the actual MethodDocs and displaying them.

(Depending on the operation mode of godoc, the input to go/doc
is a pre-filtered AST with all non-exported nodes removed. Non-
exported anonymous fields are not even seen by go/doc in this
case, and it is impossible to collect associated (even exported)
methods. A correct fix will require some more significant re-
engineering; AST filtering will have to happen later, possibly
inside go/doc.)

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5500055

pombredanne/go-deleteme,dsriram/golang,apparentlymart/golang,tv42/old-go,pombredanne/go-deleteme,gnanderson/go,pombredanne/go-deleteme,apparentlymart/golang,gnanderson/go,gnanderson/go,tv42/old-go,apparentlymart/golang,gnanderson/go,apparentlymart/golang,dsriram/golang,dsriram/golang,dsriram/golang,tv42/old-go,pombredanne/go-deleteme,dsriram/golang,apparentlymart/golang,pombredanne/go-deleteme,dsriram/golang,pombredanne/go-deleteme,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,tv42/old-go,apparentlymart/golang,gnanderson/go,dsriram/golang,tv42/old-go,tv42/old-go,gnanderson/go,gnanderson/go