Split GenerateNotNullAssertionsTests into standard box and bytecode tests

compiler/testData/codegen/bytecodeText/notNullAssertions/assertionForNotNullCaptured.kt

@@ -0,0 +1,12 @@
+// IGNORE_BACKEND: JVM_IR
+// Missing IMPLICIT_NOTNULL casts
+
+class A<T> {
+    fun add(element: T) {}
+}
+
+public fun <R : Any> foo(x: MutableCollection<in R>, block: java.util.AbstractList<R>) {
+    x.add(block.get(0))
+}
+
+// 1 checkExpressionValueIsNotNull