RFR (XXS) : 8202037: Split slow ctw_1 tests

[Ekaterina Pavlova]

Hi all,

please review this extra small change which splits slow ctw_1 test group.
Also moved slow compiler tests into hotspot_slow_compiler group.

     JBS: https://bugs.openjdk.java.net/browse/JDK-8202037
  webrev: http://cr.openjdk.java.net/~epavlova//8202037/webrev.00/index.html

Thanks,
-katya

p.s.
  Igor Ignatyev volunteered to sponsor this change.