cinterop tool should add ExperimentalForeignApi to all generated
declarations, to indicate their experimental status and discourage using
them in public Kotlin API. But the same considerations are applicable
to forward declarations (cnames.*, objcnames.*), which are generated not
by cinterop tool, but directly by the compiler.
This commit adds ExperimentalForeignApi to those compiler-generated
classes.
^KT-58362
Svyatoslav Scherbina
cba955cb3e