Support SAM conversion in psi2ir

SAM conversion takes a function value (function type or a subtype),
and produces a SAM interface value.

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrTypeOperatorCall.kt

@@ -27,7 +27,8 @@ enum class IrTypeOperator {
     IMPLICIT_INTEGER_COERCION,
     SAFE_CAST,
     INSTANCEOF,
-    NOT_INSTANCEOF;
+    NOT_INSTANCEOF,
+    SAM_CONVERSION;
 }
 
 interface IrTypeOperatorCall : IrExpression {