[oe] [meta-java] OpenJDK-8 fixes and updates

[André Draszik]

Hi,

This series addresses a few OpenJDK-8 issues:

Highlights are:
* compilation on gcc < v7 host compilers was broken
* compilation on gcc v8 (cross) compilers produced non-working binaries
* update  to the latest 8u172b11 release

This series was tested on:
* qemux86-64 (with & without security flags, host gcc 6.3.0, target gcc 8)
* qemuarm64 (with & without security flags, host gcc 4.8.4 & 6.3.0, target gcc 8)
* qemuarm64 (host gcc 7.3.0, target gcc 7.3.0)

Note that yocto's gcc 8 update completely broke qemuarm support, but I'll
hopefully address this by importing the aarch32 openjdk port into this layer.