fix corner cases with new.target (#4784)

test/compress/functions.js

@@ -5753,22 +5753,102 @@ issue_4725_2: {
     node_version: ">=4"
 }
 
-new_target: {
+new_target_1: {
     input: {
-        console.log(typeof new function() {
-            return new.target;
-        }, function() {
+        new function f() {
+            console.log(new.target === f);
+        }();
+        console.log(function() {
             return new.target;
         }());
     }
     expect: {
-        console.log(typeof new function() {
-            return new.target;
-        }(), function() {
+        new function f() {
+            console.log(new.target === f);
+        }();
+        console.log(function() {
             return new.target;
         }());
     }
-    expect_stdout: "function undefined"
+    expect_stdout: [
+        "true",
+        "undefined",
+    ]
+    node_version: ">=6"
+}
+
+new_target_2: {
+    input: {
+        new function(a) {
+            if (!new.target)
+                console.log("FAIL");
+            else if (a)
+                console.log("PASS");
+            else
+                new new.target(new.target.length);
+        }();
+    }
+    expect: {
+        new function(a) {
+            if (!new.target)
+                console.log("FAIL");
+            else if (a)
+                console.log("PASS");
+            else
+                new new.target(new.target.length);
+        }();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+new_target_collapse_vars: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        new function(a) {
+            if (a)
+                console.log("PASS");
+            else
+                new new.target(new.target.length);
+        }(0);
+    }
+    expect: {
+        new function(a) {
+            if (a)
+                console.log("PASS");
+            else
+                new new.target(new.target.length);
+        }(0);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+new_target_reduce_vars: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        new function(a) {
+            if (a)
+                console.log("PASS");
+            else
+                new new.target(new.target.length);
+        }(0);
+    }
+    expect: {
+        new function(a) {
+            if (a)
+                console.log("PASS");
+            else
+                new new.target(new.target.length);
+        }(0);
+    }
+    expect_stdout: "PASS"
     node_version: ">=6"
 }
 

test/ufuzz/index.js

@@ -149,6 +149,7 @@ var SUPPORT = function(matrix) {
     for_of: "for (var a of []);",
     generator: "function* f(){}",
     let: "let a;",
+    new_target: "function f() { new.target; }",
     nullish: "0 ?? 0",
     rest: "var [...a] = [];",
     rest_object: "var {...a} = {};",
@@ -1401,13 +1402,16 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
             createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
                 s.push(
                     instantiate + makeFunction(name) + "(" + createParams(save_async, save_generator) + "){",
-                    strictMode(),
-                    defns()
+                    strictMode()
                 );
+                var add_new_target = SUPPORT.new_target && VALUES.indexOf("new.target") < 0;
+                if (add_new_target) VALUES.push("new.target");
+                s.push(defns());
                 if (instantiate) for (var i = rng(4); --i >= 0;) {
                     s.push((in_class ? "if (this) " : "") + createThisAssignment(recurmax, stmtDepth, canThrow));
                 }
                 s.push(_createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
+                if (add_new_target) VALUES.splice(VALUES.indexOf("new.target"), 1);
             });
             generator = save_generator;
             async = save_async;