godoc: add URL mode m=methods

If set, all methods are shown, not just those
of non-exported anonynous fields.

This change will only become functional once
CL 5576057 is submitted.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5599048

src/cmd/godoc/doc.go

@@ -131,7 +131,8 @@ shown, and only an identifier index but no full text search index is created.
 The presentation mode of web pages served by godoc can be controlled with the
 "m" URL parameter; it accepts a comma-separated list of flag names as value:
 
-	all	show documentation for all (not just exported) declarations
+	all	show documentation for all declarations, not just the exported ones
+	methods	show all embedded methods, not just those of unexported anonymous fields
 	src	show the original source code rather then the extracted documentation
 	text	present the page in textual (command-line) form rather than HTML
 	flat	present flat (not indented) directory listings using full paths

src/cmd/godoc/godoc.go

@@ -867,6 +867,7 @@ type PageInfoMode uint
 
 const (
 	noFiltering PageInfoMode = 1 << iota // do not filter exports
+	allMethods                           // show all embedded methods
 	showSource                           // show source code, do not extract documentation
 	noHtml                               // show result in textual form, do not generate HTML
 	flatDir                              // show directory in a flat (non-indented) manner
@@ -875,6 +876,7 @@ const (
 // modeNames defines names for each PageInfoMode flag.
 var modeNames = map[string]PageInfoMode{
 	"all":     noFiltering,
+	"methods": allMethods,
 	"src":     showSource,
 	"text":    noHtml,
 	"flat":    flatDir,
@@ -1088,6 +1090,9 @@ func (h *httpHandler) getPageInfo(abspath, relpath, pkgname string, mode PageInf
 			if mode&noFiltering != 0 {
 				m = doc.AllDecls
 			}
+			if mode&allMethods != 0 {
+				m |= doc.AllMethods
+			}
 			pdoc = doc.New(pkg, path.Clean(relpath), m) // no trailing '/' in importpath
 		} else {
 			// show source code