Previously, assert was just a regular function and its argument used to
be computed on each call (even if assertions are disabled on JVM).
This change adds support for 3 new behaviours of assert:
* always-enable (independently from -ea on JVM)
* always-disable (independently from -ea JVM)
* runtime/jvm (compile the calls like javac generates assert-operator)
* legacy (leave current eager semantics) - this already existed
Default behaviour is legacy for now.
The behavior is changed based on -Xassertions flag.
#KT-7540: Fixed
