[llvm] [libsycl] Move and rename the shared library (PR #188770)

[Sergey Semenov via llvm-commits]

sergey-semenov wrote:

>What's the default of LLVM_ENABLE_PER_TARGET_RUNTIME_DIR on Linux?

On by default: https://github.com/llvm/llvm-project/blob/5a0ef1f63151b03a2ef0269464f331fa2db806f8/llvm/CMakeLists.txt#L1047

>SYCL RT is not just internal compiler runtime. That's a library which must be available system wide even if compiler is not installed as that's also a runtime dependency of the applications built by the compiler.

How is that different from the other runtime projects here, like libcxx or liboffload?

https://github.com/llvm/llvm-project/pull/188770