COMP: Fix SSE2 build errors with WrapITK on GCC 4.9. (ForRelease)

As of gcc 4.9 the cmake test for emmintrin.h no longer depends on SSE2 support actually being enabled.
Gccxml has a problem with this since its parser is based on gcc-4.2.

See ITK-3299

Change-Id: I0dbd504e5202beae8f68930f3a21d2a348158b26
Merge branch 'FixSSE2_release' into release

Change-Id: I62a76c1b3c9df380b8cae6ad7a61accf4707dc7c