Revert "[SYCL] Support online_compiler::compile compiled with pre-C++11 ABI"

[aelovikov-intel]

Reverts #16179

template <source_language Lang>
__SYCL_EXPORT std::vector<byte> online_compiler<Lang>::compile_impl(
    detail::string_view Src, detail::string_view DeviceStepping,
    const std::vector<detail::string_view> &Options) {

accesses this->CompileToSPIRVHandle which is laid out after std::string data member:

  /// Target device stepping (implementation defined)
  std::string DeviceStepping;

  /// Handles to helper functions used by the implementation.
  void *CompileToSPIRVHandle = nullptr;

resulting in ABI incompatibility.