[SYCL][NATIVECPU] Fix linker errors for WorkGroup collective functions

[PietroGhg]

This PR fixes some link-time error related to WorkGroup collective functions:

• adds overloads for the _Float16 data type and the __spirv_GroupBroadcast function, which leads to undefined reference linker errors.
• Makes it so the call to clang-offload-deps is not emitted by the driver: the call introduced an llvm.used array, which contained function pointers to the kernels which prevented eliminating those functions from the module even when they are not needed anymore (due to inlining). This lead to other undefined reference linker errors for WorkGroup collectives.

[PietroGhg]

Hi @intel/llvm-reviewers-runtime, after https://github.com/intel/llvm/pull/15142 the ownership of libdevice/nativecpu* has changed, but your approval is still required for this PR, could someone take a look? Thank you

[PietroGhg]

@intel/llvm-gatekeepers this looks ready to merge, thank you