https://bugs.webkit.org/show_bug.cgi?id=123682

Source/JavaScriptCore: 

Reviewed by Geoffrey Garen.
        
Inside llvmForJSC, we override assertion-related functions and funnel them
into g_llvmTrapCallback(). We also now register a fatal error handler inside
the library and funnel that into g_llvmTrapCallback, and have
initializeAndGetJSCLLVMAPI() take such a callback as an argument.
        
Inside JSC, we no longer call LLVMInstallFatalErrorHandler() but instead we
pass WTFLogAlwaysAndCrash() as the trap callback for llvmForJSC.

* llvm/InitializeLLVM.cpp:
(JSC::initializeLLVM):
* llvm/InitializeLLVMPOSIX.cpp:
(JSC::initializeLLVMPOSIX):
* llvm/library/LLVMExports.cpp:
(llvmCrash):
(initializeAndGetJSCLLVMAPI):
* llvm/library/LLVMOverrides.cpp:
(raise):
(__assert_rtn):
(abort):
* llvm/library/LLVMTrapCallback.h: Added.

Source/WTF: 

Reviewed by Geoffrey Garen.
        
Give JSC some new toys to play with for crash handling.

* wtf/Assertions.cpp:
* wtf/Assertions.h:

Tools: 

Reviewed by Geoffrey Garen.
        
Need to disable LLVM's crash overrides so that we can do our own crash overrides.

* Scripts/configure-llvm:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158509 268f45cc-cd09-0410-ab3c-d52691b4dbfc