It is not obvious from 'KotlinSingleTargetExtension' that calling
into 'target' is unsafe and it might throw.
Ordering code (especially with Android) is hard:
It is not clear when the target will become available.
The Future (and forAllTargets implementation) is intended
to make working with targets generically more safe.
KT-61634
Move K/N dependencies handling logic into gradle plugins:
`NativeDependenciesDownloader` is instantiated in
`:kotlin-native:dependencies` and provides a single configuration that
contains all directories with the dependencies. The configuration has
a variant for each target.
`NativeDependencies` is instantiated by projects that require native
dependencies (i.e. previously used to depend on
`:kotlin-native:dependencies:update`). This plugin creates a configuration
that by default depends on `:kotlin-native:dependencies`. Its extension
provides `llvmDependency`, `libffiDependency`, `hostPlatformDependency`,
`targetDependency()` to depend on the parts needed for the project and
provides accessors `llvmPath`, `libffiPath`, `hostPlatform` that are
safe to use during configuration time, but which do not automatically
resolve those dependencies.
`llvmDir`, `*LibffiDir` properties on `:kotlin-native` are removed
completely, as their use is replaced by `NativeDependencies`. As a
consequence, `evaluationDependsOn(":kotlin-native:dependencies")` is
also gone.
All direct dependencies on `:kotlin-native:dependencies:update` are
replaced with dependencies on specific parts via `NativeDependencies`
And read commonized klibs in execution time only.
it is possible only when rootOutputDirectoryProperty is marked as
OutputDirectory.
```kotlin
class Producer {
@get:OutputDirectory
val foo: RegularFileProperty
@get:Internal
val bar: RegularFileProperty
}
val foo = producer.flatMap { it.foo.map { it.listFiles() } }
val bar = producer.flatMap { it.bar.map { it.listFiles() } }
```
`foo` file collection will be evaluated at execution time.
Because `Producer.foo` is an OutputDirectory and its content unknown
during configuration time.
But `bar` file collection will be evaluated at configuration time.
Because according to gradle model it is not Output and therefore
its content can be evaluated before task execution.
^KT-61359 Verification Pending
Sergej Jaskiewicz