the assember was getting fiddly. It now masks out only the undefined
or unimplemented parts of the feature set bits, so it now passes through
all the non-ISA-related feature bits to clients.
It also leaves the vendor ID string unmolested, so that clients can
extract vendor-specific information like extended brand strings and
cache/TLB configuration info.
It does, however, implement some Valgrind-specific requests at 0xd8000000,
though at present the only functionality is the ValgrindVCPU signature.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2236