RFR (XS) 8201359: Incorrect header guards after JDK-8198949 (Modularize arraycopy stub routine GC barriers)

[Aleksey Shipilev]

Spotted this when pulling upstream changes to Epsilon sandbox branch.

Trivial RFE:
  https://bugs.openjdk.java.net/browse/JDK-8201359

Fix:
  http://cr.openjdk.java.net/~shade/8201359/webrev.01/

Testing: x86_64 build

Thanks,
-Aleksey