SYCL introduces unnecessary(?) dependency on Sema

https://github.com/intel/llvm/pull/3301 added Sema library as a dependency for Frontend, CodeGen and a couple of other libraries, which doesn't make sense to me. According to @DenisBakhvalov, it required to build clang in "shared libraries" configuration.

This looks very suspicious. Community version doesn't have this dependency. https://github.com/llvm/llvm-project/blob/main/clang/lib/CodeGen/CMakeLists.txt#L92
+@erichkeane, @AaronBallman, do you know the reason for clang's CodeGen to depend on Sema library?

_Originally posted by @bader in https://github.com/intel/llvm/pull/3301#discussion_r588063845_