fix corner case in inline (#5068)

fixes #5067

lib/compress.js

@@ -2207,7 +2207,7 @@ merge(Compressor.prototype, {
                         fn = fn.fixed_value();
                     }
                     if (!(fn instanceof AST_Lambda)) return !node.is_expr_pure(compressor);
-                    if (def && recursive_ref(compressor, def)) return true;
+                    if (def && recursive_ref(compressor, def, fn)) return true;
                     if (fn.collapse_scanning) return false;
                     fn.collapse_scanning = true;
                     var replace = can_replace;
@@ -9481,7 +9481,7 @@ merge(Compressor.prototype, {
                 && !fn.uses_arguments
                 && !fn.pinned()
                 && !(fn.name && fn instanceof AST_LambdaExpression)
-                && (exp === fn || !recursive_ref(compressor, def = exp.definition())
+                && (exp === fn || !recursive_ref(compressor, def = exp.definition(), fn)
                     && fn.is_constant_expression(find_scope(compressor)))
                 && !has_spread
                 && (value = can_flatten_body(stat))

test/compress/functions.js

@@ -6398,3 +6398,18 @@ issue_5061_2: {
         "bar",
     ]
 }
+
+issue_5067: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f = function() {
+            f();
+        };
+    }
+    expect: {}
+}