RFR [XS] [jdk11] : 8233203: fix non-product build on AIX when compiling with xlc16/legacy-xlc

[Baesken, Matthias]

Hello, please review the following small  AIX related fix.
It is a JDK11 only change ,  and  fixes issues  when building JDK11  with xlc16/legacy xlc .
Currently the product build of jdk11   already works with xlc16 ; however  without this change ,  the (fast)debug build  still fails
  because  we call into  operator new   ( operator_new.cpp)     from   Iostream_init::Iostream_init()()   and this  leads to  a failing build .

( The described  issue   was not seen  when  using  the old  xlc12  for the build . )


Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8233203

http://cr.openjdk.java.net/~mbaesken/webrevs/8233203.0/

Thanks, Matthias