[IR][tests] New test: non-abstract callable member in abstract class becomes abstract

^KT-53663

compiler/testData/klibABI/nonAbstractFunctionInAbstractClassBecomesAbstract/lib1/l1.kt.0

@@ -0,0 +1,7 @@
+package lib1
+
+abstract class A {
+    fun foo(): Int = 42
+    open fun bar(): Int = 42
+    open fun baz(): Int = 42
+}

compiler/testData/klibABI/nonAbstractFunctionInAbstractClassBecomesAbstract/lib1/l1.kt.1

@@ -0,0 +1,7 @@
+package lib1
+
+abstract class A {
+    abstract fun foo(): Int
+    abstract fun bar(): Int
+    abstract fun baz(): Int
+}

compiler/testData/klibABI/nonAbstractFunctionInAbstractClassBecomesAbstract/lib1/module.info

@@ -0,0 +1,12 @@
+STEP 0:
+    dependencies: stdlib
+    modifications:
+        U : l1.kt.0 -> l1.kt
+STEP 1:
+    dependencies: stdlib
+    modifications:
+        U : l1.kt.1 -> l1.kt
+STEP 2:
+    dependencies: stdlib
+    modifications:
+        U : l1.kt.0 -> l1.kt