enhance side_effects (#5578)

lib/compress.js

@@ -10497,6 +10497,14 @@ Compressor.prototype.compress = function(node) {
                     })).optimize(compressor);
                 }
                 break;
+            } else if (compressor.option("side_effects")
+                && exp instanceof AST_Call
+                && exp.args.length == 1
+                && is_undeclared_ref(exp.expression)
+                && exp.expression.name == "Object") {
+                var call = self.clone();
+                call.expression = maintain_this_binding(compressor, self, exp, exp.args[0]);
+                return call.optimize(compressor);
             }
         }
         if (compressor.option("unsafe_Function")
@@ -11131,24 +11139,22 @@ Compressor.prototype.compress = function(node) {
     });
 
     OPT(AST_New, function(self, compressor) {
+        if (compressor.option("unsafe")) {
+            var exp = self.expression;
+            if (is_undeclared_ref(exp)) switch (exp.name) {
+              case "Array":
+              case "Error":
+              case "Function":
+              case "Object":
+              case "RegExp":
+                return make_node(AST_Call, self, self).transform(compressor);
+            }
+        }
         if (compressor.option("sequences")) {
             var seq = lift_sequence_in_expression(self, compressor);
             if (seq !== self) return seq.optimize(compressor);
         }
         if (compressor.option("unused")) drop_unused_call_args(self, compressor);
-        if (compressor.option("unsafe")) {
-            var exp = self.expression;
-            if (is_undeclared_ref(exp)) {
-                switch (exp.name) {
-                  case "Object":
-                  case "RegExp":
-                  case "Function":
-                  case "Error":
-                  case "Array":
-                    return make_node(AST_Call, self, self).transform(compressor);
-                }
-            }
-        }
         return self;
     });
 

test/compress/side_effects.js

@@ -318,6 +318,32 @@ unsafe_string_replace: {
     expect_stdout: "PASS"
 }
 
+unsafe_Object_call: {
+    options = {
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        var o = {
+            f: function(a) {
+                console.log(a ? this.p : "FAIL 1");
+            },
+            p: "FAIL 2",
+        }, p = "PASS";
+        Object(o.f)(42);
+    }
+    expect: {
+        var o = {
+            f: function(a) {
+                console.log(a ? this.p : "FAIL 1");
+            },
+            p: "FAIL 2",
+        }, p = "PASS";
+        (0, o.f)(42);
+    }
+    expect_stdout: "PASS"
+}
+
 drop_value: {
     options = {
         side_effects: true,