go/printer: print pointer designation of type parameters in contracts

Also: Align start or methods and type lists.
Change-Id: Icae3be0ebcbc633d2ed88ff6f620dc078a7c698e

src/go/printer/nodes.go

@@ -1107,13 +1107,16 @@ func (p *printer) expr(x ast.Expr) {
 
 func (p *printer) constraint(x *ast.Constraint) {
 	p.print(x.Pos())
+	if x.Star.IsValid() {
+		p.print(token.MUL)
+	}
 	if x.Param == nil {
 		// embedded contract
 		p.expr(x.Types[0])
 		return
 	}
 	// method or list of types
-	p.print(x.Param, blank)
+	p.print(x.Param, vtab)
 	if len(x.MNames) > 0 && x.MNames[0] != nil {
 		// single method
 		// For now we only support a single method

src/go/printer/testdata/contracts.golden

@@ -13,23 +13,34 @@ contract (
 )
 
 contract _(T) {
-	T int
-	T float32, string, struct{}
+	T	int
+	T	float32, string, struct{}
 	(C0)
 	C0()
 	C1(T)
 	C2(T, T, T)
-	T m()
-	T int
+	T	m()
+	T	int
 }
 
 contract _(A, B, C) {
-	A a()	// only a will be printed for now
-	B a()
+	A	a()	// only a will be printed for now
+	B	a()
 
 	// a 1st comment
 	// a 2nd comment
-	C a()
+	C	a()
+}
+
+contract _(A, Aa, Aaaa, Aaaaa) {
+	A	m()
+	Aa	m()
+	*Aaa	m()
+	*Aaaa	m()
+	Aaaaa	int
+
+	A	string
+	Aaaaa	float32
 }
 
 type _(type T) interface{}

src/go/printer/testdata/contracts.input

@@ -32,6 +32,17 @@ contract _(A, B, C) {
         C a()
 }
 
+contract _(A, Aa, Aaaa, Aaaaa) {
+        A m()
+        Aa m()
+        *Aaa m()
+        *Aaaa m()
+        Aaaaa int
+
+        A string
+        Aaaaa float32
+}
+
 type _(type T) interface{}
 type _(type T) interface{
         m(T)