Replace heap object access macros with functions and move them to the heap class

Replace heap object access macros with functions and move them to the heap class

BUG=

[Hannes Payer (out of office), 2014-04-30 07:47:25]

I think this is going in the right direction, cool stuff.

If performance is not *significantly* negatively impacted we should get rid of
the macros.

https://codereview.chromium.org/253293003/diff/1/src/heap.h
File src/heap.h (right):

https://codereview.chromium.org/253293003/diff/1/src/heap.h#newcode686
src/heap.h:686: static inline Object* read_field(HeapObject* p, int offset);
Our INLINE macro may force inlining of these functions.

https://codereview.chromium.org/253293003/diff/1/src/objects-inl.h
File src/objects-inl.h (right):

https://codereview.chromium.org/253293003/diff/1/src/objects-inl.h#newcode99
src/objects-inl.h:99: #define SYNCHRONIZED_SMI_ACCESSORS(holder, name, offset)  
 \
The synchronized accessors should also live in heap, i.e., all methods using
them should be part of heap.

[Jarin, 2016-03-30 07:28:54]

Description was changed from

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Replace heap object access macros with functions and move them to the heap class

BUG=
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to

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Replace heap object access macros with functions and move them to the heap class

BUG=
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