[benchmark] Breadcrumbs: swap PRNG implementations

[palimondo]

Replaced local LCRNG implementation with SplitMix64 from TestUtils.

[palimondo]

@swift-ci please benchmark

[swift-ci]

Code size: -O

TEST	OLD	NEW	DELTA	RATIO
Improvement
Breadcrumbs.o	45701	45221	-1.1%	1.01x

Code size: -Osize

TEST	OLD	NEW	DELTA	RATIO
Improvement
Breadcrumbs.o	45214	43662	-3.4%	1.04x

How to read the data

The tables contain differences in performance which are larger than 8% and differences in code size which are larger than 1%.

If you see any unexpected regressions, you should consider fixing the
regressions before you merge the PR.

Noise: Sometimes the performance results (not code size!) contain false
alarms. Unexpected regressions which are marked with '(?)' are probably noise.
If you see regressions which you cannot explain you can try to run the
benchmarks again. If regressions still show up, please consult with the
performance team (@eeckstein).

Hardware Overview

  Model Name: Mac Pro
  Model Identifier: MacPro6,1
  Processor Name: 8-Core Intel Xeon E5
  Processor Speed: 3 GHz
  Number of Processors: 1
  Total Number of Cores: 8
  L2 Cache (per Core): 256 KB
  L3 Cache: 25 MB
  Memory: 64 GB

[palimondo]

@swift-ci please smoke test

[palimondo]

@swift-ci please test Linux platform

[palimondo]

Ups. Forgot to type smoke… 💨

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 28adf81

[palimondo]

@swift-ci please smoke test Linux platform