go/types: fix a couple of internal comments

Change-Id: If0e8fbb05c09ee7c64e1aa6b0aa2ade35a70df8a
Reviewed-on: https://go-review.googlesource.com/135696Reviewed-by: Alan Donovan <adonovan@google.com>

src/go/types/decl.go

@@ -65,7 +65,7 @@ func objPathString(path []Object) string {
 }
 
 // objDecl type-checks the declaration of obj in its respective (file) context.
-// See check.typ for the details on def and path.
+// For the meaning of def, see Checker.definedType, in typexpr.go.
 func (check *Checker) objDecl(obj Object, def *Named) {
 	if trace {
 		check.trace(obj.Pos(), "-- checking %s %s (objPath = %s)", obj.color(), obj, objPathString(check.objPath))

src/go/types/typexpr.go

@@ -16,7 +16,7 @@ import (
 
 // ident type-checks identifier e and initializes x with the value or type of e.
 // If an error occurred, x.mode is set to invalid.
-// For the meaning of def, see check.typExpr, below.
+// For the meaning of def, see Checker.definedType, below.
 //
 func (check *Checker) ident(x *operand, e *ast.Ident, def *Named) {
 	x.mode = invalid