A couple of dict optimizations

[tekknolagi]

• wip faster dict init
• faster dict.copy
• Make dictEnsureCapacity inlinable

[github-actions]

{
  "django_minimal_requests": {
    "benchmark": "django_minimal_requests",
    "cg_instructions before": 704138,
    "cg_instructions now": 699765,
    "cg_instructions ∆": "-0.6%",
    "interpreter_args": [],
    "interpreter_name": "pyro",
    "version before": "ad9c64750bcd3f5c45a30b762851649b7aafdae4",
    "version now": "d767ea1b4bcffce4757d7f1530dd7666395b31f6"
  }
}

[github-actions]

Summary

Metric	Average	Best	Worst	Notes
cg_instructions	-0.0%	bench_pickle -0.1%	nbody -0.0%	typically < 0.2% noise

Benchmark details

Base vs. New

benchmark	cg_instructions
2to3	-0.1%
bench_base64	-0.0%
bench_compile	-0.0%
bench_pickle	-0.1%
deltablue	-0.0%
fannkuch	-0.0%
go	-0.0%
loadproperty	-0.0%
nbody	-0.0%
nqueens	-0.0%
pyflate	-0.0%
pystone	-0.0%
richards	-0.0%

CPython vs New

benchmark	cg_instructions
2to3	-10.2%
bench_base64	-38.7%
bench_compile	1105.8%
bench_pickle	-27.9%
deltablue	-64.7%
fannkuch	-3.4%
go	-64.1%
loadproperty	-75.2%
nbody	20.7%
nqueens	33.3%
pyflate	-33.7%
pystone	-71.9%
richards	-80.0%

Base

benchmark	cg_instructions
2to3	2,304,774,544
bench_base64	2,952,632,194
bench_compile	2,981,997,285
bench_pickle	2,988,584,000
deltablue	1,452,752,191
fannkuch	5,403,091,680
go	1,890,210,970
loadproperty	433,038,944
nbody	9,404,718,896
nqueens	2,950,979,983
pyflate	9,589,666,836
pystone	1,120,934,745
richards	963,112,783

New

benchmark	cg_instructions
2to3	2,303,334,461
bench_base64	2,952,529,901
bench_compile	2,981,311,667
bench_pickle	2,986,004,415
deltablue	1,452,619,288
fannkuch	5,402,980,143
go	1,890,070,878
loadproperty	432,923,392
nbody	9,404,601,074
nqueens	2,950,861,631
pyflate	9,589,543,877
pystone	1,120,809,367
richards	962,988,460

CPython

benchmark	cg_instructions
2to3	2,563,583,466
bench_base64	4,820,251,425
bench_compile	247,244,604
bench_pickle	4,144,248,177
deltablue	4,109,404,086
fannkuch	5,594,152,878
go	5,264,709,714
loadproperty	1,747,778,599
nbody	7,793,868,213
nqueens	2,213,179,964
pyflate	14,468,032,843
pystone	3,981,591,948
richards	4,821,561,681