cmd/compile: move Node.Pack to Node.Name.Pack

$ sizeof -p cmd/compile/internal/gc Node
Node 232
$

Change-Id: I4be025f4ec11f882f24ae7582821d36d3b122b77
Reviewed-on: https://go-review.googlesource.com/10526
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/cmd/compile/internal/gc/dcl.go b/src/cmd/compile/internal/gc/dcl.go
index fc2f14a..2a88861 100644
--- a/src/cmd/compile/internal/gc/dcl.go
+++ b/src/cmd/compile/internal/gc/dcl.go
@@ -174,6 +174,10 @@
 		return
 	}
 
+	if n.Name == nil {
+		// named OLITERAL needs Name; most OLITERALs don't.
+		n.Name = new(Name)
+	}
 	n.Lineno = int32(parserline())
 	s := n.Sym