fix corner case in inline (#5537)

fixes #5536

lib/compress.js

@@ -1598,8 +1598,7 @@ Compressor.prototype.compress = function(node) {
     AST_Destructured.DEFMETHOD("convert_symbol", convert_destructured);
     function convert_symbol(type, process) {
         var node = make_node(type, this, this);
-        process(node, this);
-        return node;
+        return process(node, this) || node;
     }
     AST_SymbolDeclaration.DEFMETHOD("convert_symbol", convert_symbol);
     AST_SymbolRef.DEFMETHOD("convert_symbol", convert_symbol);
@@ -10548,9 +10547,9 @@ Compressor.prototype.compress = function(node) {
         return try_evaluate(compressor, self);
 
         function make_void_lhs(orig) {
-            return make_node(AST_Dot, orig, {
+            return make_node(AST_Sub, orig, {
                 expression: make_node(AST_Array, orig, { elements: [] }),
-                property: "e",
+                property: make_node(AST_Number, orig, { value: 0 }),
             });
         }
 
@@ -10905,6 +10904,7 @@ Compressor.prototype.compress = function(node) {
             }));
 
             function process(ref, name) {
+                if (name.unused) return make_void_lhs(name);
                 var def = name.definition();
                 def.assignments++;
                 def.references.push(ref);