Add support for toolchain compilation with LLVM_LINK_LLVM_DYLIB option

[fineg74]

No description provided.

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[fineg74]

The purpose of this PR is to break a circular dependency between GenXIntrinsics and llvm libraries to allow building of llvm with shared library configuration. This PR is a first step for this purpose and the follow up PR in llvm branch will use the results of this PR to complete the configuration change

The failing tests are :

• Unable to locate package clang-15 for In-tree build & tests / Linux (Release, NoSharedLibs)
• Segmentation fault for a test in Out-of-tree build & tests / Linux (Release)
• Unable to locate package clang-15 for In-tree build & tests / Linux (Debug, NoSharedLibs)
• Segmentation fault for a test in Out-of-tree build & tests / Linux (Debug)
• Unable to locate package clang-15 for In-tree build & tests / Linux (Release, EnableSharedLibs)
  Since the the requested change deals with build configuration rather than with code and does not introduce any new dependency, it is not related to clang-15 package error and is not related to test segmentation fault.

[AlexeySachkov]

@fineg74, could you please simply merge main into your branch and push the PR again? I'm sure that we made some fixes to the CI and everything should pass now

[fineg74]

@AlexeySachkov I merged the latest main and pushed into PR. Do I need to resubmit the PR ?

[aaronpuchert]

Paradoxically, our builds with LLVM_LINK_LLVM_DYLIB=ON worked before this change, and this change breaks them. We use LLVM_LINK_LLVM_DYLIB because we don't want the static libraries to be used, in fact we don't even ship them. So the DISABLE_LLVM_LINK_LLVM_DYLIB is one problem. Another is that we want shared libraries, but this hardcodes the library as static.

The change seems like a workaround for an issue in intel/llvm that causes regressions for other downstream users. Looking at intel/llvm#6413, I think the patch should have been applied there, or at least limited to that particular build scenario and not all builds with LLVM_LINK_LLVM_DYLIB. Something like

if(INTEL_LLVM AND LLVM_LINK_LLVM_DYLIB)
  add_llvm_library(LLVMSPIRVLib STATIC DISABLE_LLVM_LINK_LLVM_DYLIB ...)
else()
  add_llvm_library(LLVMSPIRVLib ...)
endif()