Revert "Adding SSE2 mulhi"

The SSE2 multiply is twice as slow as the standard code!
This reverts commit 76876f5ca197c86d5e65317c09f24690139e5cf0, reversing
changes made to 7ea222022b0b4212a029afbc3655a9d0acfea5d0.
Revert "Enabled SSE2 in Visual C++"

This reverts commit 3475e1789c326bf4f88b1d6ac42f931065d38e8a.
minor ATI identification fix