remove clang_dxc from semahlsl testing

Author: inbelic

clang/test/CodeGenDirectX/unsupported_intrinsic.hlsl

@@ -1,5 +1,6 @@
 // REQUIRES: directx-registered-target
-// RUN: not %clang_dxc -T lib_6_3 %s 2>&1 | FileCheck %s
+// RUN: not %clang_cc1 -triple dxilv1.3-unknown-shadermodel6.3-library \
+// RUN:  -finclude-default-header -S -o - %s 2>&1 | FileCheck %s
 
 // CHECK: error: Unsupported intrinsic llvm.vector.reduce.and.v4i32 for DXIL lowering