Make SNaN verification universal for all arches.

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index 4e7cf8f1dfb20faf28f30c3d9e861cf57fe773ba..059406e3dc21193be8ae9d5ba7be6d75d9ab5564 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -390,8 +390,12 @@ void FixedDoubleArray::FixedDoubleArrayVerify() {
   for (int i = 0; i < length(); i++) {
     if (!is_the_hole(i)) {
       uint64_t value = get_representation(i);
-      CHECK((value & V8_UINT64_C(0x7FF8000000000000)) !=
-                V8_UINT64_C(0x7FF0000000000000) ||
+      uint64_t unexpected =
+          bit_cast<uint64_t>(std::numeric_limits<double>::quiet_NaN()) &
+          V8_UINT64_C(0x7FF8000000000000);
+      // Create implementation specific sNaN by inverting relevant bit.
+      unexpected ^= V8_UINT64_C(0x0008000000000000);
+      CHECK((value & V8_UINT64_C(0x7FF8000000000000)) != unexpected ||
             (value & V8_UINT64_C(0x0007FFFFFFFFFFFF)) == V8_UINT64_C(0));
     }
   }