[X86][SSE] Legal XMM Register Class ordering for SSE1

[X86][SSE] Legal XMM Register Class ordering for SSE1

It turns out we have a number of places that just grab the first type attached to a register class for various reasons. This is fine unless for some reason that type isn't legal on the current target, such as for SSE1 which doesn't support v16i8/v8i16/v4i32/v2i64 - all of which were included before 4f32 in the class.

Given that this is such a rare situation I've just re-ordered the types and placed the float types first.

Fix for PR16133

Differential Revision: http://reviews.llvm.org/D14787

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253773 91177308-0d34-0410-b5e6-96231b3b80d8