testBox failure on i386

[nickrasmussen]

from #3:

ilmbase 2.0.0 builds on i386, however the testsuite still fails with:
extendBy() point for type V2f
extendBy() point for type V2d
lt-ImathTest: testBox.cpp:253: void {anonymous}::testExtendByPoint(const char*) [with T = Imath_2_0::Vec2]: Assertion `b.min == p && b.max == p' failed.
/bin/bash: line 4: 7000 Aborted ${dir}$tst
FAIL: ImathTest

[ehanway-ilm]

Duplicate of #67. Since that issue has more info, including workarounds (e.g. -ffloat-store), closing this one.