[SYCL] Make spelling of Debug value for CMAKE_BUILD_TYPE variable case insensitive (#4069)

Signed-off-by: Kanaev <[email protected]>

Author: sergei

sycl/cmake/modules/AddSYCLUnitTest.cmake

@@ -6,7 +6,8 @@ macro(add_sycl_unittest test_dirname link_variant)
   # Enable exception handling for these unit tests
   set(LLVM_REQUIRES_EH 1)
 
-  if (MSVC AND CMAKE_BUILD_TYPE MATCHES "Debug")
+  string(TOLOWER "${CMAKE_BUILD_TYPE}" build_type_lower)
+  if (MSVC AND build_type_lower MATCHES "debug")
     set(sycl_obj_target "sycld_object")
     set(sycl_so_target "sycld")
   else()