[turbofan] Prevent storing signalling NaNs into holey double arrays.

test/mjsunit/compiler/regress-store-holey-double-array.js

+// Copyright 2016 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
+
+(function StoreHoleBitPattern() {
+  function g(src, dst, i) {
+    dst[i] = src[i];
+  }
+
+  var b = new ArrayBuffer(16);
+  var i32 = new Int32Array(b);
+  i32[0] = 0xFFF7FFFF;
+  i32[1] = 0xFFF7FFFF;
+  i32[3] = 0xFFF7FFFF;
+  i32[4] = 0xFFF7FFFF;
+  var f64 = new Float64Array(b);
+
+  var a = [,0.1];
+
+  g(f64, a, 1);
+  g(f64, a, 1);
+  %OptimizeFunctionOnNextCall(g);
+  g(f64, a, 0);
+
+  assertTrue(Number.isNaN(a[0]));
+})();
+
+
+(function ConvertHoleToNumberAndStore() {
+  function g(a, i) {
+    var x = a[i];
+    a[i] = +x;
+  }
+
+  var a=[,0.1];
+  g(a, 1);
+  g(a, 1);
+  %OptimizeFunctionOnNextCall(g);
+  g(a, 0);
+  assertTrue(Number.isNaN(a[0]));
+})();