Revert back 2nd stage of split semantics change and restore deprecated String.split(String).

libraries/stdlib/src/kotlin/text/Strings.kt

@@ -922,10 +922,6 @@ public fun String.splitToSequence(vararg delimiters: String, ignoreCase: Boolean
  * the beginning to the end of this string, and matches at each position the first element in [delimiters]
  * that is equal to a delimiter in this instance at that position.
  */
-public fun String.split(vararg delimiters: String, ignoreCase: Boolean = false, limit: Int = 0): List<String> =
-        splitToSequence(*delimiters, ignoreCase = ignoreCase, limit = limit).toList()
-
-deprecated("Use split(delimiters) instead.")
 public fun String.splitBy(vararg delimiters: String, ignoreCase: Boolean = false, limit: Int = 0): List<String> =
         splitToSequence(*delimiters, ignoreCase = ignoreCase, limit = limit).toList()
 

libraries/stdlib/src/kotlin/text/StringsJVM.kt

@@ -127,6 +127,12 @@ public fun String.split(regex: Pattern, limit: Int = 0): List<String>
     require(limit >= 0, { "Limit must be non-negative, but was $limit" } )
     return regex.split(this, if (limit == 0) -1 else limit).asList()
 }
+/**
+ * Splits this string around matches of the given regular expression.
+ */
+deprecated("Convert an argument to regex with toRegex or use splitBy instead.")
+public fun String.split(regex: String): Array<String> = split(regex.toRegex()).toTypedArray()
+
 
 /**
  * Returns a substring of this string starting with the specified index.