Union leads to broken function

[vchuravy]

julia> f(cond, x) = cond ? x : 0
f (generic function with 1 method)

julia> using Enzyme

julia> autodiff(f, Active, true, Active(1.0))
ERROR: LLVM error: broken function
Stacktrace:
 [1] verify
   @ ~/.julia/packages/LLVM/vQ98J/src/analysis.jl:18 [inlined]
 [2] lower_convention(functy::Type, mod::LLVM.Module, entry_f::LLVM.Function, actualRetType::Type)
   @ Enzyme.Compiler ~/src/Enzyme/src/compiler.jl:2903
 [3] codegen(output::Symbol, job::GPUCompiler.CompilerJob{Enzyme.Compiler.EnzymeTarget, Enzyme.Compiler.EnzymeCompilerParams, GPUCompiler.FunctionSpec{typeof(f), Tuple{Bool, Float64}}}; libraries::Bool, deferred_codegen::Bool, optimize::Bool, strip::Bool, validate::Bool, only_entry::Bool, parent_job::Nothing)
   @ Enzyme.Compiler ~/src/Enzyme/src/compiler.jl:3103
 [4] _thunk(job::GPUCompiler.CompilerJob{Enzyme.Compiler.EnzymeTarget, Enzyme.Compiler.EnzymeCompilerParams, GPUCompiler.FunctionSpec{typeof(f), Tuple{Bool, Float64}}})
   @ Enzyme.Compiler ~/src/Enzyme/src/compiler.jl:3473
 [5] cached_compilation(cache::Dict{UInt64, Any}, job::GPUCompiler.CompilerJob, compiler::typeof(Enzyme.Compiler._thunk), linker::typeof(Enzyme.Compiler._link))
   @ GPUCompiler ~/.julia/packages/GPUCompiler/yCkO8/src/cache.jl:90
 [6] thunk(f::typeof(f), df::Nothing, ::Type{Active}, tt::Type{Tuple{Const{Bool}, Active{Float64}}}, ::Val{Enzyme.API.DEM_ReverseModeCombined})
   @ Enzyme.Compiler ~/src/Enzyme/src/compiler.jl:3526
 [7] autodiff(::typeof(f), ::Type{Active}, ::Bool, ::Vararg{Any})
   @ Enzyme ~/src/Enzyme/src/Enzyme.jl:196
 [8] top-level scope
   @ REPL[3]:1