[SPIRV] Floating point select operands cause the machine verifier to trip

[winocm]

Here's a minimal test case that results in the failure when using llc -verify-machineinstrs:

define spir_func float @test(float %x, float %y, float %z) {
entry:
   %0 = call float @llvm.maxnum.f32(float %x, float %y)
   %1 = fcmp ogt float %0, %z
   %2 = select i1 %1, float %y, float %0
   ret float %2
}

Godbolt: https://godbolt.org/z/54K5KvdfP