JVM_IR never generate setter synthetic accessor for 'val' field

KT-49316

compiler/testData/codegen/box/syntheticAccessors/kt49316a.kt

@@ -0,0 +1,17 @@
+// TARGET_BACKEND: JVM
+
+// This test should become irrelevant after KT-35565 is fixed.
+
+fun test(foo: Foo): String {
+    return foo.s
+
+    // VAL_REASSIGNMENT not reported in unreachable code.
+    // Make sure there's no BE internal error here.
+    foo.s = "oops"
+}
+
+// CHECK_BYTECODE_LISTING
+// - there should be no synthetic accessor generated in 'Foo'
+class Foo(val s: String)
+
+fun box() = test(Foo("OK"))