Clang ESIMD lit tests rely on sycl-post-link tool

[bader]

Describe the bug
Clang :: CodeGenSYCL/esimd-accessor-ptr-md.cpp and Clang :: CodeGenSYCL/esimd-private-global.cpp invoke sycl-post-link tool, but it's not listed as a dependency, which leads to failed tests.

To Reproduce
Checkout sycl branch, configure build files and build check-clang target. It's important to not build sycl-post-link target or any other target building sycl-post-link before building check-clang.

Environment (please complete the following information):

• OS: I used Linux, but it should not be OS specific issue.
• Target device and vendor: N/A.
• DPC++ version: N/A.
• Dependencies version: N/A.

Additional context
I think we should avoid invoking this tool if possible.

[AlexeySachkov]

I think we should avoid invoking this tool if possible.

I've had related discussion with @vladimirlaz here: #3561 (comment)

I guess such tests where we need to launch several tools to check how they operate together, i.e. some integration tests are definitely needed in the project, but I'm not sure what is and/or should be the official location for them?

I was thinking that putting such tests under sycl/test should be ok, but would like to hear more opinions

[DenisBakhvalov]

The dependency on sycl-post-link in ESIMD tests wasn't real -- it was rather a leftover from previous big changes I made for SYCL-ESIMD coexistence feature.