Implement unaligned allocate and allocate heap numbers in runtime double unaligned.

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 420 matching lines @@
   LO_SPACE,    // Promoted large objects.
 
   FIRST_SPACE = NEW_SPACE,
   LAST_SPACE = LO_SPACE,
   FIRST_PAGED_SPACE = OLD_SPACE,
   LAST_PAGED_SPACE = MAP_SPACE
 };
 const int kSpaceTagSize = 3;
 const int kSpaceTagMask = (1 << kSpaceTagSize) - 1;
 
+enum AllocationAlignment { kWordAligned, kDoubleAligned, kDoubleUnaligned };
 
 // A flag that indicates whether objects should be pretenured when
 // allocated (allocated directly into the old generation) or not
 // (allocated in the young generation if the object size and type
 // allows).
 enum PretenureFlag { NOT_TENURED, TENURED };
 
 enum MinimumCapacity {
   USE_DEFAULT_MINIMUM_CAPACITY,
   USE_CUSTOM_MINIMUM_CAPACITY
@@ skipping 496 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_