requested alignment 128 is larger than 64 on armhf and s390x

[Timo Jyrinki]

See build log https://launchpadlibrarian.net/273695893/buildlog_ubuntu-yakkety-s390x.qtbase-opensource-src_5.6.1+dfsg-3ubuntu1~1_BUILDING.txt.gz searching for "alignment 128". The build errors out on s390x and armhf, and on both yakkety and xenial.

However:
- The problem only happens in one section of tests (tests/auto/corelib/tools/collections)
- The build did succeed to build in Debian unstable and earlier in experimental - but Debian doesn't have any tests enabled for qtbase-opensource-src

Related Qt code: http://code.qt.io/cgit/qt/qtbase.git/tree/src/corelib/global/qcompilerdetection.h?h=5.6.1