hg: bsd-port/jdk8: Restore endianness defines to the common compiler flags.

[glewis at eyesbeyond.com]

Changeset: 24852d5f9f36
Author:    Greg Lewis <glewis at eyesbeyond.com>
Date:      2019-02-09 10:03 -0800
URL:       http://hg.openjdk.java.net/bsd-port/jdk8/rev/24852d5f9f36

Restore endianness defines to the common compiler flags.

During the upgrade to 8u192 there was a large reorganisation of the config
rules and during the merge these defines got lost.  This primarily impacted
Math functions which returned incorrect results on little endian platforms
(such as x86_64 and x86).

! common/autoconf/flags.m4
! common/autoconf/generated-configure.sh