fourthTier: Concurrent JIT shouldn't try to recompute the CodeBlockHash as part of debug dumps, since doing so may fail if dealing with a CachedScript that doesn't have its script string handy
https://bugs.webkit.org/show_bug.cgi?id=117676

Reviewed by Sam Weinig.

Source/JavaScriptCore:

CodeBlock now caches m_hash, and the DFG Driver will force its computation if we're doing debug dumps of any kind.

Also made sure that CodeBlock::CodeBlock initializes all of its fields; it was previously missing the
initialization of m_capabilityLevelState.

* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::hash):
(JSC::CodeBlock::CodeBlock):
* bytecode/CodeBlock.h:
(CodeBlock):
* bytecode/CodeBlockHash.cpp:
(JSC::CodeBlockHash::CodeBlockHash):
* bytecode/CodeBlockHash.h:
(CodeBlockHash):
(JSC::CodeBlockHash::isSet):
(JSC::CodeBlockHash::operator!):
* dfg/DFGDriver.cpp:
(JSC::DFG::compile):

Source/WebCore:

Remove the broken hack for the concurrent JIT, since now the concurrent JIT won't use this code anymore.

No new tests because no new behavior.

* loader/cache/CachedScript.cpp:
(WebCore::CachedScript::script):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153227 268f45cc-cd09-0410-ab3c-d52691b4dbfc