[X86] Remove isel patterns that turns packed add/sub/mul/div+movss/sd into scalar...

[X86] Remove isel patterns that turns packed add/sub/mul/div+movss/sd into scalar intrinsic instructions.

This is not an optimization we should be doing in isel. This is more suitable for a DAG combine.

My main concern is a future time when we support more FPENV. Changing a packed op to a scalar op could cause us to miss some exceptions that should have occured if we had done a packed op. A DAG combine would be better able to manage this.

llvm-svn: 336971