added a test for the issue golang#22371

Change-Id: Ic250826fa2effa7920825271195e6d55b481a999

src/go/ast/commentmap_test.go

@@ -53,6 +53,8 @@ func f1() {
 	
 	// also associated with s2
 	s2() // line comment for s2
+
+	// another comment also associated with s2
 }
 // associated with f1
 // also associated with f1
@@ -87,11 +89,11 @@ var res = map[string]string{
 	"25: *ast.GenDecl":    "x\nx = 0\nalso associated with x\n",
 	"29: *ast.FuncDecl":   "f1\nassociated with f1\nalso associated with f1\n",
 	"31: *ast.ExprStmt":   " associated with s1\nalso associated with s1\n",
-	"37: *ast.ExprStmt":   "associated with s2\nalso associated with s2\nline comment for s2\n",
-	"45: *ast.FuncDecl":   "associated with f2\nf2\n",
-	"49: *ast.AssignStmt": "addition\n",
-	"49: *ast.BasicLit":   " 1\n",
-	"50: *ast.Ident":      "the very last comment\n",
+	"37: *ast.ExprStmt":   "associated with s2\nalso associated with s2\nline comment for s2\nanother comment also associated with s2\n",
+	"47: *ast.FuncDecl":   "associated with f2\nf2\n",
+	"51: *ast.AssignStmt": "addition\n",
+	"51: *ast.BasicLit":   " 1\n",
+	"52: *ast.Ident":      "the very last comment\n",
 }
 
 func ctext(list []*CommentGroup) string {
@@ -110,7 +112,7 @@ func TestCommentMap(t *testing.T) {
 	}
 	cmap := NewCommentMap(fset, f, f.Comments)
 
-	// very correct association of comments
+	// verify correct association of comments
 	for n, list := range cmap {
 		key := fmt.Sprintf("%2d: %T", fset.Position(n.Pos()).Line, n)
 		got := ctext(list)