all: use "reports whether" in godoc comments

Go documentation style for boolean funcs is to say:

    // Foo reports whether ...
    func Foo() bool

rather than "returns true if" or "returns whether".

Change-Id: I5d01c45a8867b47462ed142a49ad51bf0a319ce1
Reviewed-on: https://go-review.googlesource.com/c/151957
Reviewed-by: Elias Naur <elias.naur@gmail.com>

bind/genjava.go

@@ -372,7 +372,7 @@ func (g *JavaGen) javadoc(doc string) {
 	g.Printf("/**\n * %s */\n", html.EscapeString(doc))
 }
 
-// hasThis returns whether a method has an implicit "this" parameter.
+// hasThis reports whether a method has an implicit "this" parameter.
 func (g *JavaGen) hasThis(sName string, m *types.Func) bool {
 	sig := m.Type().(*types.Signature)
 	params := sig.Params()