llvm.is.fpclass is different from other vectorizable intrinsics in that it is overloaded on an argument type, not on the return type. Differential Revision: https://reviews.llvm.org/D148905
This reverts commit 5fc6425fb6c77052a26cf0cf7b886449fabe1af4. It is reported to cause other crashes that require a larger fix.
Differential Revision: https://reviews.llvm.org/D148803