Initialize double values before calling rempio2.

src/runtime/runtime-maths.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "src/arguments.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
 #include "src/runtime/runtime.h"
@@ skipping 47 matching lines @@
   uint64_t result = (static_cast<uint64_t>(hi) << 32) | lo;
   return *isolate->factory()->NewNumber(uint64_to_double(result));
 }
 
 
 RUNTIME_FUNCTION(Runtime_RemPiO2) {
   HandleScope handle_scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
   Factory* factory = isolate->factory();
-  double y[2];
+  double y[2] = {0.0, 0.0};
   int n = fdlibm::rempio2(x, y);
   Handle<FixedArray> array = factory->NewFixedArray(3);
   Handle<HeapNumber> y0 = factory->NewHeapNumber(y[0]);
   Handle<HeapNumber> y1 = factory->NewHeapNumber(y[1]);
   array->set(0, Smi::FromInt(n));
   array->set(1, *y0);
   array->set(2, *y1);
   return *factory->NewJSArrayWithElements(array);
 }
 
@@ skipping 159 matching lines @@
 RUNTIME_FUNCTION(RuntimeReference_IsMinusZero) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, obj, 0);
   if (!obj->IsHeapNumber()) return isolate->heap()->false_value();
   HeapNumber* number = HeapNumber::cast(obj);
   return isolate->heap()->ToBoolean(IsMinusZero(number->value()));
 }
 }
 }  // namespace v8::internal