We need this at least until we have 'dependsOn(self)' syntax.
When 'self' is nonescapable and the result is 'void', assume that 'self' depends
on a single nonescapable argument.
Pitch - https://github.com/apple/swift-evolution/pull/2305
Changes highlights:
dependsOn(paramName) and dependsOn(scoped argName) syntax
dependsOn(paramName) -> copy lifetime dependence for all parameters/self except
when we have Escapable parameters/self, we assign scope
lifetime dependence.
Allow lifetime dependence on parameters without ownership modifier.
Always infer copy lifetime dependence except when we have
Escapable parameters/self, we infer scope lifetime dependence.
Allow lifetime dependence inference on parameters without ownership modifier.
Provide APIs needed by lifetime dependence diagnostics, namely LifetimeDependenceConvention.
Reorganize the APIs so it's easy to find related functionality which
API is responsible for which functionality.
Remove the originalFunctionConvention complexity. It is no longer
needed for lifetime dependence inference, and generally should be
avoided in SIL.
Add some placeholder FIXMEs because this not a good PR in which to
change existing functionality.
