--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TreeHasher.java	Mon Sep 09 11:43:16 2019 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TreeHasher.java	Wed Nov 27 09:00:01 2019 +0100
@@ -106,6 +106,12 @@
     }
 
     @Override
+    public void visitBindingPattern(JCTree.JCBindingPattern tree) {
+        symbolHashes.computeIfAbsent(tree.symbol, k -> symbolHashes.size());
+        super.visitBindingPattern(tree);
+    }
+
+    @Override
     public void visitVarDef(JCVariableDecl tree) {
         symbolHashes.computeIfAbsent(tree.sym, k -> symbolHashes.size());
         super.visitVarDef(tree);