Make sure fixed typed array is always double aligned for doubles

src/globals.h

 // Copyright 2012 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.
 
 #ifndef V8_GLOBALS_H_
 #define V8_GLOBALS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 622 matching lines @@
   (((value) + kObjectAlignmentMask) & ~kObjectAlignmentMask)
 
 // POINTER_SIZE_ALIGN returns the value aligned as a pointer.
 #define POINTER_SIZE_ALIGN(value)                               \
   (((value) + kPointerAlignmentMask) & ~kPointerAlignmentMask)
 
 // CODE_POINTER_ALIGN returns the value aligned as a generated code segment.
 #define CODE_POINTER_ALIGN(value)                               \
   (((value) + kCodeAlignmentMask) & ~kCodeAlignmentMask)
 
+// DOUBLE_POINTER_ALIGN returns the value algined for double pointers.
+#define DOUBLE_POINTER_ALIGN(value) \
+  (((value) + kDoubleAlignmentMask) & ~kDoubleAlignmentMask)
+
 // Support for tracking C++ memory allocation.  Insert TRACK_MEMORY("Fisk")
 // inside a C++ class and new and delete will be overloaded so logging is
 // performed.
 // This file (globals.h) is included before log.h, so we use direct calls to
 // the Logger rather than the LOG macro.
 #ifdef DEBUG
 #define TRACK_MEMORY(name) \
   void* operator new(size_t size) { \
     void* result = ::operator new(size); \
     Logger::NewEventStatic(name, result, size); \
@@ skipping 290 matching lines @@
 inline FunctionKind WithObjectLiteralBit(FunctionKind kind) {
   kind = static_cast<FunctionKind>(kind | FunctionKind::kInObjectLiteral);
   DCHECK(IsValidFunctionKind(kind));
   return kind;
 }
 } }  // namespace v8::internal
 
 namespace i = v8::internal;
 
 #endif  // V8_GLOBALS_H_