Move the FSO bailout to the beginning of the pass.

[atrick]

This way we catch the DeadFunctionArgs optimization too, which is a
separate sub-pass.

[Part of the series of already-approved pass manager commits from:
https://github.com//pull/22445]

[atrick]

@swift-ci test

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 80d502c

[atrick]

@swift-ci smoke test linux

[atrick]

@swift-ci smoke test linux

[atrick]

@swift-ci benchmark

[swift-ci]

Performance: -O

Improvement	OLD	NEW	DELTA	RATIO
DataReplaceMediumBuffer	10100	9400	-6.9%	1.07x (?)

Code size: -O

Performance: -Osize

Improvement	OLD	NEW	DELTA	RATIO
DictionaryBridgeToObjC_Access	923	765	-17.1%	1.21x (?)

Code size: -Osize

Performance: -Onone

Improvement	OLD	NEW	DELTA	RATIO
ObjectiveCBridgeStubFromNSDateRef	4830	4390	-9.1%	1.10x (?)

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