cmd/compile: move Node.Param, Node.Funcdepth into Node.Name; remove Node.Walkgen

$ sizeof -p cmd/compile/internal/gc Node
Node 176
$

Change-Id: Ibf1ab531a60d4af8a0c242c0e504f4fd50cd5b36
Reviewed-on: https://go-review.googlesource.com/10530
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/src/cmd/compile/internal/gc/swt.go b/src/cmd/compile/internal/gc/swt.go
index 6f04328..82a6457 100644
--- a/src/cmd/compile/internal/gc/swt.go
+++ b/src/cmd/compile/internal/gc/swt.go
@@ -169,10 +169,10 @@
 			if nvar != nil {
 				if ll != nil && ll.Next == nil && ll.N.Type != nil && !Istype(ll.N.Type, TNIL) {
 					// single entry type switch
-					nvar.Param.Ntype = typenod(ll.N.Type)
+					nvar.Name.Param.Ntype = typenod(ll.N.Type)
 				} else {
 					// multiple entry type switch or default
-					nvar.Param.Ntype = typenod(n.Type)
+					nvar.Name.Param.Ntype = typenod(n.Type)
 				}
 
 				typecheck(&nvar, Erv|Easgn)