Add test showing scala/bug#6067 is fixed

Author: Philippus

shared/src/test/scala/scala/util/parsing/combinator/t6067.scala

@@ -0,0 +1,19 @@
+import scala.util.parsing.combinator._
+
+import org.junit.Test
+import org.junit.Assert.assertEquals
+
+class t6067 extends RegexParsers {
+  object TestParser extends RegexParsers {
+    def p: TestParser.ParseResult[TestParser.~[List[String], String]] = parseAll(rep(commit("a")) ~ "b", "aaab")
+  }
+
+  val expected = """[1.4] error: 'a' expected but 'b' found
+
+aaab
+   ^"""
+  @Test
+  def test: Unit = {
+    assertEquals(expected, TestParser.p.toString)
+  }
+}