Assertion hit while compiling kernels from Darktable

[kpet]

Compiling the attached source with the following options

clspv source.cl  -w -cl-fast-relaxed-math  -DNVIDIA=1 -I"/usr/share/darktable/kernels" -cl-single-precision-constant  -cl-kernel-arg-info   -fp16=0  -rewrite-packed-structs  -std430-ubo-layout  -decorate-nonuniform    -arch=spir  --use-native-builtins=acos,acosh,acospi,asin,asinh,asinpi,atan,atan2,atan2pi,atanh,atanpi,ceil,copysign,fabs,fdim,floor,fma,fmax,fmin,frexp,half_rsqrt,half_sqrt,isequal,isfinite,isgreater,isgreaterequal,isinf,isless,islessequal,islessgreater,isnan,isnormal,isnotequal,isordered,isunordered,ldexp,mad,rint,round,rsqrt,signbit,sqrt,tanh,trunc,  -spv-version=1.6  -max-pushconstant-size=256  -max-ubo-size=65536  -global-offset  -long-vector  -module-constants-in-storage-buffer  -cl-arm-non-uniform-work-group-size     -o compiled.spv

results in the following assertion being hit:

clspv: /mnt/work/repos/clvk/external/clspv/third_party/llvm/llvm/include/llvm/Support/Casting.h:578: decltype(auto) llvm::cast(From*) [with To = SelectInst; From = Value]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.

Darktable used to run on top of clvk (not sure it was the exact same version) so this may be a regression.

source.txt

[rjodinchr]

This is coming from FixupBuiltinsPass::fixupSqrt where the builder optimize CreateSelect because the condition is constant, thus ending up with a nullptr being cast to SelectInst asserting.
I'll push a fix for it tomorrow.