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

$ sizeof -p cmd/compile/internal/gc Node
Node 224
$

Change-Id: Id0969e8df99c43a5f6f8d77a38f20a71a467e7c6
Reviewed-on: https://go-review.googlesource.com/10527
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

src/cmd/compile/internal/gc/go.y

@@ -246,7 +246,7 @@ import_stmt:
 
 		pack := Nod(OPACK, nil, nil);
 		pack.Sym = my;
-		pack.Pkg = ipkg;
+		pack.Name.Pkg = ipkg;
 		pack.Lineno = int32($1);
 
 		if strings.HasPrefix(my.Name, ".") {
@@ -1010,7 +1010,7 @@ pexpr_no_paren:
 	{
 		if $1.Op == OPACK {
 			var s *Sym
-			s = restrictlookup($3.Name, $1.Pkg);
+			s = restrictlookup($3.Name, $1.Name.Pkg);
 			$1.Used = true;
 			$$ = oldname(s);
 			break;
@@ -1299,7 +1299,7 @@ dotname:
 	{
 		if $1.Op == OPACK {
 			var s *Sym
-			s = restrictlookup($3.Name, $1.Pkg);
+			s = restrictlookup($3.Name, $1.Name.Pkg);
 			$1.Used = true;
 			$$ = oldname(s);
 			break;
@@ -1700,7 +1700,7 @@ packname:
 			pkg = localpkg;
 		} else {
 			$1.Def.Used = true;
-			pkg = $1.Def.Pkg;
+			pkg = $1.Def.Name.Pkg;
 		}
 		$$ = restrictlookup($3.Name, pkg);
 	}

src/cmd/compile/internal/gc/lex.go

@@ -2577,7 +2577,7 @@ func mkpackage(pkgname string) {
 				// errors if a conflicting top-level name is
 				// introduced by a different file.
 				if !s.Def.Used && nsyntaxerrors == 0 {
-					pkgnotused(int(s.Def.Lineno), s.Def.Pkg.Path, s.Name)
+					pkgnotused(int(s.Def.Lineno), s.Def.Name.Pkg.Path, s.Name)
 				}
 				s.Def = nil
 				continue
@@ -2587,7 +2587,7 @@ func mkpackage(pkgname string) {
 				// throw away top-level name left over
 				// from previous import . "x"
 				if s.Def.Name != nil && s.Def.Name.Pack != nil && !s.Def.Name.Pack.Used && nsyntaxerrors == 0 {
-					pkgnotused(int(s.Def.Name.Pack.Lineno), s.Def.Name.Pack.Pkg.Path, "")
+					pkgnotused(int(s.Def.Name.Pack.Lineno), s.Def.Name.Pack.Name.Pkg.Path, "")
 					s.Def.Name.Pack.Used = true
 				}
 

src/cmd/compile/internal/gc/subr.go

@@ -378,7 +378,7 @@ func Nod(op int, nleft *Node, nright *Node) *Node {
 	case ONAME:
 		n.Name = new(Name)
 		n.Param = new(Param)
-	case OLABEL:
+	case OLABEL, OPACK:
 		n.Name = new(Name)
 	case ODCLFIELD:
 		n.Param = new(Param)

src/cmd/compile/internal/gc/syntax.go

@@ -33,9 +33,6 @@ type Node struct {
 	Curfn *Node // function for local variables
 	Param *Param
 
-	// OPACK
-	Pkg *Pkg
-
 	// Escape analysis.
 	Escflowsrc *NodeList // flow(this, src)
 	Escretval  *NodeList // on OCALLxxx, list of dummy return values
@@ -91,9 +88,10 @@ type Node struct {
 	Hasbreak    bool // has break statement
 }
 
-// Name holds Node fields used only by ONAME nodes.
+// Name holds Node fields used only by named nodes (ONAME, OPACK, some OLITERAL).
 type Name struct {
 	Pack      *Node // real package for import . names
+	Pkg       *Pkg  // pkg for OPACK nodes
 	Heapaddr  *Node // temp holding heap address of param
 	Inlvar    *Node // ONAME substitute while inlining
 	Defn      *Node // initializing assignment

src/cmd/compile/internal/gc/y.go

@@ -1272,7 +1272,7 @@ yydefault:
 
 			pack := Nod(OPACK, nil, nil)
 			pack.Sym = my
-			pack.Pkg = ipkg
+			pack.Name.Pkg = ipkg
 			pack.Lineno = int32(yyDollar[1].i)
 
 			if strings.HasPrefix(my.Name, ".") {
@@ -2169,7 +2169,7 @@ yydefault:
 		{
 			if yyDollar[1].node.Op == OPACK {
 				var s *Sym
-				s = restrictlookup(yyDollar[3].sym.Name, yyDollar[1].node.Pkg)
+				s = restrictlookup(yyDollar[3].sym.Name, yyDollar[1].node.Name.Pkg)
 				yyDollar[1].node.Used = true
 				yyVAL.node = oldname(s)
 				break
@@ -2431,7 +2431,7 @@ yydefault:
 		{
 			if yyDollar[1].node.Op == OPACK {
 				var s *Sym
-				s = restrictlookup(yyDollar[3].sym.Name, yyDollar[1].node.Pkg)
+				s = restrictlookup(yyDollar[3].sym.Name, yyDollar[1].node.Name.Pkg)
 				yyDollar[1].node.Used = true
 				yyVAL.node = oldname(s)
 				break
@@ -2861,7 +2861,7 @@ yydefault:
 				pkg = localpkg
 			} else {
 				yyDollar[1].sym.Def.Used = true
-				pkg = yyDollar[1].sym.Def.Pkg
+				pkg = yyDollar[1].sym.Def.Name.Pkg
 			}
 			yyVAL.sym = restrictlookup(yyDollar[3].sym.Name, pkg)
 		}