[SYCL][libdevice] Build for spirv64 on Linux (#13302)

Otherwise we will hit problems with compiling with
`-fsycl-targets=spirv64`.

Eventually we will need to expand this for the non-JIT `spirv64`
targets, but those aren't supported today.

We only build on Linux today because of ptrdiff_t size differences
causing compiler errors on Windows.

Found this also while working on thinLTO.

---------

Signed-off-by: Sarnie, Nick <nick.sarnie@intel.com>

libdevice/cmake/modules/SYCLLibdevice.cmake

@@ -22,6 +22,15 @@ string(CONCAT sycl_targets_opt
  "spir64_fpga-unknown-unknown,"
  "spir64-unknown-unknown")
 
+if (NOT WIN32)
+ # Don't build for spirv64 on Windows due to
+ # some type size difference issues.
+ # Build on once Windows once internal tracker is fixed.
+ string(APPEND
+ sycl_targets_opt
+ ",spirv64-unknown-unknown")
+endif()
+
 set(compile_opts
  # suppress an error about SYCL_EXTERNAL being used for
  # a function with a raw pointer parameter.