[SYCL][CMake] Properly enable -pie hardening flag (#19447)

We rely on CMake to set the right set of compliation and link flags to
enable positition independent code and position independent execution.

Before this commit, necessary compliation flags were applied just fine,
but link flags were missing. To get link flags, some extra CMake
functions should be called.

Author: AlexeySachkov

llvm/cmake/modules/AddSecurityFlags.cmake

@@ -107,7 +107,10 @@ macro(append_common_extra_security_flags)
   # Position Independent Execution
   # We rely on CMake to set the right -fPIE flags for us, but it must be
   # explicitly requested
-  if (NOT CMAKE_POSITION_INDEPENDENT_CODE)
+  if (CMAKE_POSITION_INDEPENDENT_CODE)
+    include(CheckPIESupported)
+    check_pie_supported()
+  else()
     message(FATAL_ERROR "To enable all necessary security flags, CMAKE_POSITION_INDEPENDENT_CODE must be set to ON")
   endif()