Handle out-of-memory conditions with JSC Ropes with a JS exception, rather than crashing.
Switch from using fastMalloc to tryFastMalloc, pass an ExecState to record the exception on.

Reviewed by Oliver Hunt.

JavaScriptCore: 

* API/JSCallbackObjectFunctions.h:
(JSC::::toString):
* API/JSValueRef.cpp:
(JSValueIsStrictEqual):
* JavaScriptCore.exp:
* bytecompiler/BytecodeGenerator.cpp:
(JSC::BytecodeGenerator::emitEqualityOp):
* debugger/DebuggerCallFrame.cpp:
(JSC::DebuggerCallFrame::functionName):
(JSC::DebuggerCallFrame::calculatedFunctionName):
* interpreter/Interpreter.cpp:
(JSC::Interpreter::callEval):
(JSC::Interpreter::privateExecute):
* jit/JITStubs.cpp:
(JSC::DEFINE_STUB_FUNCTION):
* profiler/ProfileGenerator.cpp:
(JSC::ProfileGenerator::addParentForConsoleStart):
* profiler/Profiler.cpp:
(JSC::Profiler::willExecute):
(JSC::Profiler::didExecute):
(JSC::Profiler::createCallIdentifier):
(JSC::createCallIdentifierFromFunctionImp):
* profiler/Profiler.h:
*...