Enable boolean type test on GPU. (intel#257)

intel/llvm#2458 fixes issue 2264.

Author: bader

SYCL/Basic/boolean.cpp

@@ -1,7 +1,3 @@
-// TODO: Enable compilation w/o -fno-sycl-early-optimizations option.
-// See https://github.com/intel/llvm/issues/2264 for more details.
-// XFAIL: gpu && (level_zero || opencl)
-
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
 // RUN: %HOST_RUN_PLACEHOLDER %t.out
 // RUN: %CPU_RUN_PLACEHOLDER %t.out