https://bugs.webkit.org/show_bug.cgi?id=87172

Reviewed by Oliver Hunt and Phil Pizlo.

This enables MarkedBlock to own non-trivial sub-objects that require
destruction. It also fixes a FIXME about casting a CopiedBlock to a
MarkedBlock at destroy time.

CopiedBlock and MarkedBlock now accept an allocation chunk at create
time and return it at destroy time. Their client is expected to
allocate, recycle, and destroy these chunks.

* heap/BlockAllocator.cpp:
(JSC::BlockAllocator::releaseFreeBlocks):
(JSC::BlockAllocator::blockFreeingThreadMain): Don't call MarkedBlock::destroy
because we expect that to be called before a block is put on our free
list now. Do manually deallocate our allocation chunk because that's
our job now.

* heap/BlockAllocator.h:
(BlockAllocator):
(JSC::BlockAllocator::allocate): Allocate never fails now. This is a
cleaner abstraction because only one object does all the VM allocation
and deallocation. Caching is an implementation detail.

(JSC::BlockAllocator::deallocate): We take an allocation chunk argument
instead of a block because we now expect the block to have been destroyed 
before we recycle its memory. For convenience, we still use the HeapBlock
class as our linked list node. This is OK because HeapBlock is a POD type.

* heap/CopiedBlock.h:
(CopiedBlock):
(JSC::CopiedBlock::create):
(JSC::CopiedBlock::destroy):
(JSC::CopiedBlock::CopiedBlock): Added proper create and destroy functions,
to match MarkedBlock.

* heap/CopiedSpace.cpp:
(JSC::CopiedSpace::tryAllocateOversize):
(JSC::CopiedSpace::tryReallocateOversize):
(JSC::CopiedSpace::doneCopying):
(JSC::CopiedSpace::getFreshBlock):
(JSC::CopiedSpace::freeAllBlocks):
* heap/CopiedSpaceInlineMethods.h:
(JSC::CopiedSpace::recycleBlock): Make sure to call destroy before
returning a block to the BlockAllocator. Otherwise, our destructors
won't run. (If we get this wrong now, we'll get a compile error.)

* heap/HeapBlock.h:
(JSC::HeapBlock::HeapBlock): const!

* heap/MarkedAllocator.cpp:
(JSC::MarkedAllocator::allocateBlock): No need to distinguish between
create and recycle -- MarkedBlock always accepts memory allocated by
its client now.

* heap/MarkedBlock.cpp:
(JSC::MarkedBlock::create): Don't allocate memory -- we assume that we're
passed already-allocated memory, to clarify the responsibility for VM
recycling.

(JSC::MarkedBlock::destroy): Do run our destructor before giving back
our VM -- that is the whole point of this patch.

(JSC::MarkedBlock::MarkedBlock):
* heap/MarkedBlock.h:
(MarkedBlock):
* heap/MarkedSpace.cpp: const!

(JSC::MarkedSpace::freeBlocks): Make sure to call destroy before
returning a block to the BlockAllocator. Otherwise, our destructors
won't run. (If we get this wrong now, we'll get a compile error.)


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@118083 268f45cc-cd09-0410-ab3c-d52691b4dbfc