[IR] Add MFVC generation tests

#KT-1179

compiler/testData/codegen/box/valueClasses/throwingMFVCReassignments.kt

@@ -0,0 +1,33 @@
+// WITH_STDLIB
+// TARGET_BACKEND: JVM_IR
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses
+
+@JvmInline
+value class DPoint(val x: Double, val y: Double)
+
+class PointBox(var value: DPoint)
+
+fun box(): String {
+    var p = DPoint(1.0, 2.0)
+    try {
+        p = DPoint(3.0, error("Failure"))
+    } catch (_: Exception) {
+    }
+    if (p != DPoint(1.0, 2.0)) {
+        return "Partially reassigned variable"
+    }
+    
+    val box = PointBox(p)
+
+    try {
+        box.value = DPoint(3.0, error("Failure"))
+    } catch (_: Exception) {
+    }
+    
+    if (box.value != DPoint(1.0, 2.0)) {
+        return "Partially reassigned field"
+    }
+    
+    return "OK"
+}