SSE1 test suite.

Adds a _failing_ test which refers to _each_ intrinsic provided by Intel Intrinsic reference in `xmmintrin.h`. Not to be merged yet , unless we skip the test from being run in the suite. The test passes if built and run natively with gcc or clang.
It'd be nicer to do a __builtin_shufflevector(__a, __a, 3, 2, 1, 0) and a plain store here, so that we don't depend quite so much on the optimizer to reconstruct this.