RFR(XS): 8075515: AIX: cleanup xlc options and use -bernotok to detect missing symbols at build time

[Volker Simonis]

Hi,

can somebody please review and sponsor this change (because it
requires re-generation of generated-configure.sh):

http://cr.openjdk.java.net/~simonis/webrevs/2015/8075515/
https://bugs.openjdk.java.net/browse/JDK-8075515

This change adds -bernotok (which is xlc's equivalent for gcc's '-z
defs') to the jdk build to detect missing symbols already at compile
time (for the hotspot build this was already done by change "8067923
AIX: link libjvm.so with -bernotok to detect missing symbols at build
time...").

It also removes '-q64' from the CC, CXX and LD flags in flags.m4
because '-q64' is already set by
PLATFORM_SET_COMPILER_TARGET_BITS_FLAGS in platform.m4.

Thank you and best regards,
Volker