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
Otherwise some tools break (e.g. CheckMethodAdapter in ASM, used in generic
signature writer) because they expect class names to be Java identifiers.
Some tests fixed, some will be fixed in future commits