[SYCLomatic] Remove unittest (quite out of date) (#2470)

Signed-off-by: Jiang, Zhiwei <[email protected]>

Author: zhiweij1

clang/unittests/CMakeLists.txt

@@ -52,5 +52,4 @@ add_subdirectory(Rename)
 add_subdirectory(Index)
 add_subdirectory(InstallAPI)
 add_subdirectory(Serialization)
-add_subdirectory(DPCT)
 add_subdirectory(Support)