[CK] Fix/suppress clang lifetimebound warnings with staging compiler. (#6550)

## Motivation

New changes from upstream llvm-project cause an avalanche of warnings in
CK. Gonna disable them by ignoring the
lifetime-safety-intra-tu-suggestions flag until a better permanent
solution is found.

## Technical Details

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## Test Plan

<!-- Explain any relevant testing done to verify this PR. -->

## Test Result

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## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

example/ck_tile/03_gemm/gemm_splitk_two_stage_reduce.cpp

@@ -16,6 +16,9 @@
 #include "gemm_utils.hpp"
 #include "run_gemm_example.inc"
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wlifetime-safety-intra-tu-suggestions"
+
 /**
  * @brief Tile partitioner with output offset support.
  *
@@ -961,3 +964,5 @@ int main(int argc, char* argv[])
     }
     return EXIT_SUCCESS;
 }
+
+#pragma clang diagnostic pop