ASSERTION 31891: (/home/yongheng/ChakraCore/lib/Backend/FlowGraph.cpp, line 2090) this->func->IsLoopBodyInTry() Failure: (this->func->IsLoopBodyInTry())

POC:
```javascript
function a() {
for (; 0;)
switch (b) {
case c:
try {
try {
for (;;)
try {
} finally {
switch (2) {
case d:
try {
} catch {
break
}
default:
c
}
}
} catch {
}
} catch {
}
}
}
for (;;)
a()
```

ch version: `ch version 1.12.0.0-beta`, git hash `33db8efd9f02cd528a7305391d7d10765a2e85f3`

In release build, it triggers a segmentation fault.
Stack dump:
```
#0 0x00007ffff34eec32 in FlowGraph::Build() () from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#1 0x00007ffff3508871 in Func::TryCodegen() () from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#2 0x00007ffff3508360 in Func::Codegen(Memory::JitArenaAllocator*, JITTimeWorkItem*, ThreadContextInfo*, ScriptContextInfo*, JITOutputIDL*, Js::EntryPointInfo*, FunctionJITRuntimeInfo const*, JITTimePolymorphicInlineCacheInfo*, void*, Js::ScriptContextProfiler*, bool) () from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#3 0x00007ffff36ce5d4 in NativeCodeGenerator::CodeGen(Memory::PageAllocatorBase, Memory::PageSegmentBase >*, CodeGenWorkItemIDL*, JITOutputIDL&, bool, Js::EntryPointInfo*) () from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#4 0x00007ffff36cebf0 in NativeCodeGenerator::CodeGen(Memory::PageAllocatorBase, Memory::PageSegmentBase >*, CodeGenWorkItem*, bool) () from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#5 0x00007ffff36cfbfc in NativeCodeGenerator::Process(JsUtil::Job*, JsUtil::ParallelThreadData*) ()
from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#6 0x00007ffff371e46e in JsUtil::BackgroundJobProcessor::Process(JsUtil::Job*, JsUtil::ParallelThreadData*) ()
from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#7 0x00007ffff371e81e in JsUtil::BackgroundJobProcessor::Run(JsUtil::ParallelThreadData*) ()
from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#8 0x00007ffff371d189 in JsUtil::BackgroundJobProcessor::StaticThreadProc(void*) ()
from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#9 0x00007ffff340ba5f in CorUnix::CPalThread::ThreadEntry(void*) ()
from /home/yongheng/ChakraCore/out/Release/libChakraCore.so
#10 0x00007ffff73646db in start_thread (arg=0x7ff7f26e0700) at pthread_create.c:463
#11 0x00007ffff654a88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
```