cosmetics (rename method param)
(cherry picked from commit 4b63206)
get rid of splitString
(cherry picked from commit 2d588ef)
startsWith/endsWith/contains as intrinsic
(cherry picked from commit af56078)
invoke as function intrinsic
DescriptorPredicate#apply — descriptor cannot be null
(cherry picked from commit 3bfa5b4)
KT-2323
cleanup strings code
(cherry picked from commit 8f7cccd)