methods: fix exported/unexported bug

Fix case where last method was exported after a new exported method
(from a different type) is defined afterwards.

methods.go

@@ -81,6 +81,7 @@ func (m *MethodsValidator) Validate(v *ast.FuncDecl, fset *token.FileSet) error
 
 	if m.lastType != rcvType.Name {
 		m.sortedTypes.identType = "Type"
+		m.sortedMethods = sortedNamesValidator{}
 		if err := validateSorted(&m.sortedTypes, rcvType, false); err != nil {
 			return err
 		}

methods_test.go

@@ -30,6 +30,11 @@ func TestMethodsValidator_Validate(t *testing.T) {
 			"methods_sorted_type_ok.go",
 			false,
 		},
+		{
+			"OK: sorted exported/unexported",
+			"methods_sorted_unexported_ok.go",
+			false,
+		},
 		{
 			"Error: not defined in file",
 			"methods_not_defined.go",

testdata/methods_sorted_unexported_ok.go

@@ -0,0 +1,14 @@
+package testdata
+
+type (
+	MethodSortedTypeUnexported_A struct{}
+	MethodSortedTypeUnexported_B struct{}
+)
+
+func (MethodSortedTypeUnexported_A) A()  {}
+func (MethodSortedTypeUnexported_A) B()  {}
+func (*MethodSortedTypeUnexported_A) c() {}
+
+//-
+
+func (MethodSortedTypeUnexported_B) A() {}