Replace all throw error(...) with just error(...)

`throw` is not needed in this case, because `error(...)` already
  raises exception (so `throw` is unreachable). Also after previous
  commit compiler reports `UNREACHABLE_CODE` warning on such `throw`

js/js.parser/src/org/jetbrains/kotlin/js/parser/sourcemaps/JSON.kt

@@ -143,7 +143,7 @@ private class JsonParser(val content: String) {
     fun parse(): JsonNode {
         val result = parseNode()
         skipSpaces()
-        if (charCode != -1) throw error("End of input expected")
+        if (charCode != -1) error("End of input expected")
         return result
     }