Temporary workaround due to KT-7502.

Correct usage of joinToString.
Test for passing multiple options.

libraries/stdlib/test/text/RegexTest.kt

@@ -84,6 +84,12 @@ class RegexTest {
         assertEquals("bye", m2.groups[2]?.value)
     }
 
+    test fun matchMultiline() {
+        val regex = "^[a-z]*$".toRegex(setOf(RegexOption.IGNORE_CASE, RegexOption.MULTILINE))
+        val matchedValues = regex.matchAll("test\r\nLine").map { it.value }.toList()
+        assertEquals(listOf("test", "Line"), matchedValues)
+    }
+
     test fun escapeLiteral() {
         val literal = """[-\/\\^$*+?.()|[\]{}]"""
         assertTrue(Regex.fromLiteral(literal).matches(literal))