deps: update V8 to 7.8.279.9

PR-URL: https://github.com/nodejs/node/pull/29694
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/deps/v8/test/mjsunit/compiler/diamond-followedby-branch.js b/deps/v8/test/mjsunit/compiler/diamond-followedby-branch.js
new file mode 100644
index 0000000000..e69a1cbeda
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/diamond-followedby-branch.js
@@ -0,0 +1,22 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+// Check that the branch elimination replace the redundant branch condition with
+// a phi node, and then the branch is folded in EffectControlLinearizationPhase.
+function foo(cond, v1, v2) {
+  cond = cond | 0;
+  var a = cond == 1 ? v1 : v2;
+  if(cond == 1) {
+    %TurbofanStaticAssert(a == v1);
+  } else {
+    %TurbofanStaticAssert(a == v2);
+  }
+}
+
+%PrepareFunctionForOptimization(foo);
+foo(1, 10, 20); foo(2, 30, 40);
+%OptimizeFunctionOnNextCall(foo);
+foo(1, 10, 20); foo(2, 30, 40);