[Driver] Update SYCL runtime library name and path for target-specific directories (#189053)
This patch updates the Clang driver to support the renamed SYCL runtime
library (libsycl.so → libLLVMSYCL.so) and its new location in
target-specific directories. These changes align with PR
#[188770](https://github.com/llvm/llvm-project/pull/188770), which
standardizes the SYCL runtime library naming and directory structure to
match other LLVM runtime libraries.
**Changes**
**Library Naming**
- **Old**: libsycl.so
- **New**: libLLVMSYCL.so
**Directory Structure**
Both build and install directories now use target-specific
subdirectories:
- **Old:** lib/libsycl.so
- **New:** lib/target-triple/libLLVMSYCL.so
For example, on x86_64-unknown-linux-gnu:
- **Old**: build/lib/libsycl.so → install/lib/libsycl.so
- **New**: build/lib/x86_64-unknown-linux-gnu/libLLVMSYCL.so →
install/lib/x86_64-unknown-linux-gnu/libLLVMSYCL.so