[llvm-branch-commits] [llvm-remarkutil] Introduce summary tool (PR #160549)

[Tobias Stadler via llvm-branch-commits]

https://github.com/tobias-stadler created https://github.com/llvm/llvm-project/pull/160549

This tool provides a harness for implementing different strategies that
summarize many remarks (possibly from multiple translation units) into
new summary remarks. The remark summaries can then be viewed using tools
like `opt-viewer`.

The first summary strategy is `--inline-callees`, which generates
remarks that summarize the per-callee inline statistics for functions
that appear in inling remarks. This is useful for troubleshooting
inlining issues/regressions on large codebases.