Fix for the HWCAP2 aux vector.

Fix for the HWCAP2 aux vector.

The support assumed that if HWCAP2 is present that the system also supports
ISA2.07.  That assumption is not correct as we have found a few systems (OS)
where the HWCAP2 entry is present but the ISA2.07 bit is not set.  This patch
fixes the assertion test to specifically check the ISA2.07 support bit setting
in the HWCAP2 and vex_archinfo->hwcaps variable.  The setting for the
ISA2.07 support must be the same in both variables if the HWCAP2 entry exists.

This patch updates Vagrind bugzilla 345695.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15257