So far, function effects only included escape effects.
This change adds side-effects (but they are not computed, yet).
It also involves refactoring of the existing escape effects.
Also the SIL effect syntax changed a bit. Details are in docs/SIL.rst
So far, argument effects were printed in square brackets before the function name, e.g.
```
sil [escapes !%0.**, !%1, %1.c*.v** => %0.v**] @foo : $@convention(thin) (@guaranteed T) -> @out S {
bb0(%0 : $*S, %1 : @guaranteed $T):
...
```
As we are adding more argument effects, this becomes unreadable.
To make it more readable, print the effects after the opening curly brace, and print a separate line for each argument. E.g.
```
sil [ossa] @foo : $@convention(thin) (@guaranteed T) -> @out S {
[%0: noescape **]
[%1: noescape, escape c*.v** => %0.v**]
bb0(%0 : $*S, %1 : @guaranteed $T):
...
```
Add a flag `analyzeAddresses` for distinguishing address vs value escape analysis. This is simpler than handling that in the visitUse/visitDef closures.
Also, fix a related bug, which let an address, which is escaping to a function, get unnoticed.
Store a list of argument effects in a function, which specify if and how arguments escape.
Such effects can be specified in the Swift source code (for details see docs/ReferenceGuides/UnderscoredAttributes.md) or derived in an optimization pass.
For details see the documentation in SwiftCompilerSources/Sources/SIL/Effects.swift.
