Revert "[clang][ssaf][NFC] Move SSAF flags from FrontendOptions to a dedicated SSAFOptions" (#204686)
Reverts llvm/llvm-project#204621
Broke a Windows bot:
https://github.com/llvm/llvm-project/pull/204621#issuecomment-4746295964
https://lab.llvm.org/buildbot/#/builders/46/builds/36811
```
FAILED: ... project\clang\lib\Frontend\CompilerInvocation.cpp
tools\clang\include\clang/Options/Options.inc(9974): error C2065: 'SSAFOpts': undeclared identifier
tools\clang\include\clang/Options/Options.inc(9975): note: see reference to function template instantiation 'auto GenerateSSAFArgs::<lambda_fd4588547196dccacaf54a707a47a2b4>::operator ()<T>(const T &) const' being compiled
with
[
T=std::vector<std::string,std::allocator<std::string>>
]
```