[vala] vala: Fix bootstrap with valac >= 0.16.1

[Rico Tzschichholz <ricotz src gnome org>]

commit 3279c5831bde814f73c0182a4de8663ebc2b1ed1
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sat Nov 17 22:21:20 2018 +0100

    vala: Fix bootstrap with valac >= 0.16.1

 vala/valaclass.vala | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
---
diff --git a/vala/valaclass.vala b/vala/valaclass.vala
index 5d8e27592..fdaabc7c5 100644
--- a/vala/valaclass.vala
+++ b/vala/valaclass.vala
@@ -323,19 +323,19 @@ public class Vala.Class : ObjectTypeSymbol {
 
        public override void add_constructor (Constructor c) {
                switch (c.binding) {
-               case INSTANCE:
+               case MemberBinding.INSTANCE:
                        if (constructor != null) {
                                Report.error (c.source_reference, "class already contains a constructor");
                        }
                        constructor = c;
                        break;
-               case CLASS:
+               case MemberBinding.CLASS:
                        if (class_constructor != null) {
                                Report.error (c.source_reference, "class already contains a class 
constructor");
                        }
                        class_constructor = c;
                        break;
-               case STATIC:
+               case MemberBinding.STATIC:
                        if (static_constructor != null) {
                                Report.error (c.source_reference, "class already contains a static 
constructor");
                        }
@@ -348,19 +348,19 @@ public class Vala.Class : ObjectTypeSymbol {
 
        public override void add_destructor (Destructor d) {
                switch (d.binding) {
-               case INSTANCE:
+               case MemberBinding.INSTANCE:
                        if (destructor != null) {
                                Report.error (d.source_reference, "class already contains a destructor");
                        }
                        destructor = d;
                        break;
-               case CLASS:
+               case MemberBinding.CLASS:
                        if (class_destructor != null) {
                                Report.error (d.source_reference, "class already contains a class 
destructor");
                        }
                        class_destructor = d;
                        break;
-               case STATIC:
+               case MemberBinding.STATIC:
                        if (static_destructor != null) {
                                Report.error (d.source_reference, "class already contains a static 
destructor");
                        }