FTBFS: src/amd/llvm/ac_llvm_util.c:248:4: error: implicit declaration of function ‘LLVMAddIPSCCPPass’ (LLVM C interface removed upstream)

Error on builds with recent versions of LLVM 17:

../src/amd/llvm/ac_llvm_util.c: In function ‘ac_create_passmgr’:
../src/amd/llvm/ac_llvm_util.c:248:4: error: implicit declaration of function ‘LLVMAddIPSCCPPass’; did you mean ‘LLVMAddSCCPPass’? [-Werror=implicit-function-declaration]
  248 |    LLVMAddIPSCCPPass(passmgr);
      |    ^~~~~~~~~~~~~~~~~
      |    LLVMAddSCCPPass

The LLVM C interface was removed upstream in commit b677d0753c0. The replacement seems to be: use llvm::IPSCCPPass() from llvm/Transforms/IPO/SCCP.h directly, from what I understand. But that would probably require the new pass manager and AC is not yet using that, but is using the legacy pass manager with llvm::legacy::PassManagerBase.

I don't think I do have the time available to convert all of AC to the new interface, but I would be more than willing to test any patches for this.