Fix NPE in JetPsiUtil (EA-43298)
Make the exception message in JvmClassName helpful
Fix codegen of do-while condition

The condition of a do-while loop can use variables declared in the loop
(variables can only be declared inside a block). Previously this behaviour
caused crash because after the block was generated, all variables declared
inside that block were gone from myFrameMap

 #KT-3280 Fixed