Remove stdlib and runtime dependencies on Foundation and CF

[Catfish-Man]

Relanding #26630, with some fixes and improvements (now also decouples from CF properly!)

Fixes rdar://34198279

[Catfish-Man]

@swift-ci please test

[Catfish-Man]

@swift-ci please benchmark

[swift-ci]

Performance: -O

Regression	OLD	NEW	DELTA	RATIO
LessSubstringSubstring	40	45	+12.5%	0.89x
EqualSubstringSubstringGenericEquatable	40	45	+12.5%	0.89x
EqualSubstringString	40	45	+12.5%	0.89x
LessSubstringSubstringGenericComparable	40	45	+12.5%	0.89x
ObjectiveCBridgeStubFromNSDateRef	3820	4220	+10.5%	0.91x (?)
EqualSubstringSubstring	41	45	+9.8%	0.91x
String.data.Medium	87	94	+8.0%	0.93x (?)
Improvement	OLD	NEW	DELTA	RATIO
IterateData	1444	1315	-8.9%	1.10x (?)
RandomShuffleLCG2	768	704	-8.3%	1.09x
RemoveWhereMoveInts	37	34	-8.1%	1.09x (?)
Array2D	7520	6928	-7.9%	1.09x (?)
RemoveWhereSwapInts	65	60	-7.7%	1.08x (?)
MapReduce	398	369	-7.3%	1.08x
FlattenListLoop	5199	4833	-7.0%	1.08x (?)
MapReduceAnyCollection	398	370	-7.0%	1.08x
Set.subtracting.Empty.Box	15	14	-6.7%	1.07x (?)

Code size: -O

Performance: -Osize

Regression	OLD	NEW	DELTA	RATIO
LessSubstringSubstring	40	45	+12.5%	0.89x
EqualSubstringString	40	45	+12.5%	0.89x
LessSubstringSubstringGenericComparable	40	45	+12.5%	0.89x
ObjectiveCBridgeStubFromNSDateRef	3720	4140	+11.3%	0.90x (?)
SortLettersInPlace	515	569	+10.5%	0.91x (?)
EqualSubstringSubstring	41	45	+9.8%	0.91x
EqualStringSubstring	41	45	+9.8%	0.91x
EqualSubstringSubstringGenericEquatable	41	45	+9.8%	0.91x
Improvement	OLD	NEW	DELTA	RATIO
UTF8Decode_InitFromData_ascii	257	236	-8.2%	1.09x (?)
Data.hash.Empty	74	68	-8.1%	1.09x (?)
Array2D	7520	6928	-7.9%	1.09x
NSStringConversion.UTF8	840	775	-7.7%	1.08x (?)
UTF8Decode_InitFromBytes_ascii	327	302	-7.6%	1.08x (?)
RemoveWhereMoveInts	40	37	-7.5%	1.08x (?)
RemoveWhereSwapInts	67	62	-7.5%	1.08x (?)
ObjectiveCBridgeFromNSSetAnyObjectToStringForced	98500	91500	-7.1%	1.08x (?)
ObjectiveCBridgeFromNSSetAnyObjectToString	77500	72000	-7.1%	1.08x (?)
FlattenListLoop	5284	4919	-6.9%	1.07x (?)

Code size: -Osize

Performance: -Onone

Regression	OLD	NEW	DELTA	RATIO
FrequenciesUsingReduceInto	3983	4485	+12.6%	0.89x (?)
Data.hash.Small	333	364	+9.3%	0.91x (?)
ObjectiveCBridgeStubFromNSDateRef	4310	4710	+9.3%	0.92x (?)
EqualSubstringSubstringGenericEquatable	46	50	+8.7%	0.92x (?)
LessSubstringSubstringGenericComparable	46	50	+8.7%	0.92x (?)
Improvement	OLD	NEW	DELTA	RATIO
ArrayOfPOD	1147	1066	-7.1%	1.08x (?)

Code size: -swiftlibs

Improvement	OLD	NEW	DELTA	RATIO
libswiftXPC.dylib	16384	12288	-25.0%	1.33x
libswiftOpenCL.dylib	16384	12288	-25.0%	1.33x
libswiftCoreFoundation.dylib	16384	12288	-25.0%	1.33x
libswiftSwiftPrivateThreadExtras.dylib	20480	16384	-20.0%	1.25x
libswiftObjectiveC.dylib	20480	16384	-20.0%	1.25x
libswiftos.dylib	32768	28672	-12.5%	1.14x
libswiftSwiftReflectionTest.dylib	32768	28672	-12.5%	1.14x
libswiftOSLogPrototype.dylib	40960	36864	-10.0%	1.11x
libswiftSwiftPrivate.dylib	45056	40960	-9.1%	1.10x
libswiftSwiftLang.dylib	94208	90112	-4.3%	1.05x
libswiftSwiftOnoneSupport.dylib	184320	180224	-2.2%	1.02x

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: 12-Core Intel Xeon E5
  Processor Speed: 2.7 GHz
  Number of Processors: 1
  Total Number of Cores: 12
  L2 Cache (per Core): 256 KB
  L3 Cache: 30 MB
  Memory: 64 GB

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 33a00434f6ae542034affb6ff5f51ca506514bcb

[Catfish-Man]

@swift-ci please test

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 33a00434f6ae542034affb6ff5f51ca506514bcb

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 33a00434f6ae542034affb6ff5f51ca506514bcb

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 33a00434f6ae542034affb6ff5f51ca506514bcb

[Catfish-Man]

@swift-ci please test osx platform

[Catfish-Man]

@swift-ci please test os x platform

[milseman]

I know this seems pedantic, but could you add a comment after the @usableFromInline? Something to the effect of:

@usableFromInline // was @inlinable through Swift 5.1 (see comment below)

I want some indication right on the decl of the binary compatibility story, without reading comments inside the body (which may be about the implementation).

[stephentyrone]

Can we also mark these deprecated at this point, with a message that explains why they're there and not to use them?

[Catfish-Man]

Can we mark things as deprecated without breaking our own/Foundation's callsites?

[milseman]

Congrats!