[ownership] Move ownership elimination on the stdlib passed lower aggregate instrs.

[gottesmm]

No description provided.

[gottesmm]

@swift-ci test

[gottesmm]

@swift-ci smoke benchmark

[swift-ci]

Performance: -O

Regression	OLD	NEW	DELTA	RATIO
FlattenListLoop	1630	2513	+54.2%	0.65x (?)
FlattenListFlatMap	5341	6504	+21.8%	0.82x (?)
Improvement	OLD	NEW	DELTA	RATIO
StringFromLongWholeSubstring	5	4	-20.0%	1.25x

Code size: -O

Performance: -Osize

Improvement	OLD	NEW	DELTA	RATIO
StringFromLongWholeSubstring	5	4	-20.0%	1.25x

Code size: -Osize

Performance: -Onone

Regression	OLD	NEW	DELTA	RATIO
UTF8Decode_InitFromCustom_contiguous_ascii	375	438	+16.8%	0.86x (?)
UTF8Decode_InitDecoding_ascii	339	388	+14.5%	0.87x (?)
UTF8Decode_InitFromCustom_contiguous_ascii_as_ascii	480	536	+11.7%	0.90x (?)

Code size: -swiftlibs

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