fix performance regression (#5302)

fixes #5297

lib/compress.js

@@ -13262,8 +13262,7 @@ Compressor.prototype.compress = function(node) {
         def(AST_New, noop);
         def(AST_Return, function(compressor, scope, no_return, in_loop) {
             var value = this.value;
-            if (value) value = value.try_inline(compressor, scope, undefined, in_loop === "try");
-            return value || this;
+            return value && value.try_inline(compressor, scope, undefined, in_loop === "try");
         });
         function inline_sequence(compressor, scope, no_return, in_loop, node, skip) {
             var body = [], exprs = node.expressions, no_ret = no_return;

test/compress/functions.js

@@ -6146,18 +6146,21 @@ issue_4265: {
                 a;
                 var a;
             }() ]);
-            return 0;
+            return 42;
         }
-        f();
+        console.log(f());
     }
     expect: {
         function f() {
             var a;
-            return console, console.log(a), 0;
+            return console, console.log(a), 42;
         }
-        f();
+        console.log(f());
     }
-    expect_stdout: "undefined"
+    expect_stdout: [
+        "undefined",
+        "42",
+    ]
 }
 
 trailing_comma: {