Add arity 0 regression test for records.

[Cherry-picked 781c25f]

Author: yilinwei

tests/pos-java16+/java-records/FromScala.scala

@@ -1,4 +1,8 @@
 object C:
+
+  def useR0: Unit =
+    val r = R0()
+
   def useR1: Unit =
     // constructor signature
     val r = R1(123, "hello")

tests/pos-java16+/java-records/R0.java

@@ -0,0 +1 @@
+public record R0() {}