[8u] RFR (S) 8046274: Removing dependency on jakarta-regexp

[Aleksey Shipilev]

Original change:
  https://bugs.openjdk.java.net/browse/JDK-8046274
  https://hg.openjdk.java.net/jdk9/jdk9/jaxp/rev/bfc9ec1a816b

Patch does not apply cleanly to 8u, because paths are different. I have removed
src/com/sun/org/apache/regexp/ by hand. Reapplied THIRD_PARTY_README by hand. InstructionFinder.java
change applies after reshuffling.

8u webrev:
  https://cr.openjdk.java.net/~shade/8046274/webrev.8u.01/

Testing: java/xml tests, tier1

-- 
Thanks,
-Aleksey