Use SSE also for 32bit.

Without, 387's "extended precision" kicks in unpredictably, possibly changing the results of fp ops.
As GCC says: "The resulting code should be considerably faster in the majority of cases and avoid the numerical instability problems of 387 code, but may break some existing code that expects temporaries to be 80 bits."

(cherry picked from commit 686f22cbf75a3119df86f8ff2d01701b65ba707f)