RFR: 8218063: JDK-8218060 breaks build for S390

[Thomas Schatzl]

Hi all,

  as StefanK in the review thread noticed, the patch for JDK-8218060
was not correct in that while it fixed the Oracle platform builds, it
broke the S390 build.

Unfortunately I already had the change pushed.

So I reinstated the method and guarded it with #if defined(S390) the
same way as the method call is guarded.

I hope it is okay to fix this with a single fix-CR and not backing out 
JDK-8218060 first.

CR:
https://bugs.openjdk.java.net/browse/JDK-8218063
Webrev:
http://cr.openjdk.java.net/~tschatzl/8218063/webrev/
Testing:
local compilation - I can't test the S390 build

Sorry for the mess-up,
  Thomas