Revert rL349136: [llvm-exegesis] Optimize ToProcess in dbScan

Summary:
Use `vector<char> Added + vector<size_t> ToProcess` to replace `SetVector ToProcess`

We also check `Added[P]` to enqueueing a point more than once, which
also saves us a `ClusterIdForPoint_[Q].isUndef()` check.

Reviewers: courbet, RKSimon, gchatelet, john.brawn, lebedev.ri

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54442
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Patch wasn't approved and breaks buildbots

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349139 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed