[XPTI] Include path not setup correctly when building pi-trace

[Naghasan]

Describe the bug

When building pi-trace with tip sycl, the include path to xpti seems to not be configured properly.

I end up with a

llvm/sycl/tools/pi-trace/pi_trace.cpp:13:10: fatal error: xpti_trace_framework.h: No such file or directory
   13 | #include "xpti_trace_framework.h"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

I tried a fresh build and configured using the configure script in the buildbot folder (python3 buildbot/configure.py -s . -o ../build -t Release --cuda), but after this I end up with the path to opencl headers not being found:

llvm/sycl/include/CL/sycl/detail/cl.h:17:10: fatal error: CL/cl.h: No such file or directory
   17 | #include <CL/cl.h>

(I rely on the headers pulled by the project)

If I remove the add_subdirectory(pi-trace) from sycl/tools everything builds fine.

Environment (please complete the following information):

• OS: Ubuntu 20.04
• DPC++ version: ea4b8a9

[bader]

This looks like a regression introduced by e239fdf.
@alexbatashev, could you fix this ASAP, please?

[danchitnis]

Further error log info here:
#4050 (reply in thread)

[rolandschulz]

I can confirm that reverting e239fdf fixes the problem. Why don't we revert that commit until the issue is resolved?

[bader]

Done by #4144.