[x86] Fix the test to actually test things for the CPU names, add the
missing barcelona CPU which that test uncovered, and remove the 32-bit
x86 CPUs which I really wasn't prepared to audit and test thoroughly.

If anyone wants to clean up the 32-bit only x86 CPUs, go for it.

Also, if anyone else wants to try to de-duplicate the AMD CPUs, that'd
be cool, but from the looks of it wouldn't save as much as it did for
the Intel CPUs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223774 91177308-0d34-0410-b5e6-96231b3b80d8