ifelse codegen produces invalid IR

[maleadt]

As seen on PkgEval.jl:

function levenberg_marquardt(OnceDifferentiable, :; maxIter, lambda, lambda_increase = 0.1, avv!)
    MAX_LAMBDA = false
    while iterCt
        if rho
            lambda = min(lambda_increase * lambda, MAX_LAMBDA)
        end
    end
end

function lmfit(f, g, p0, AbstractArray; kwargs...)
    levenberg_marquardt(R, p0; kwargs...)
end

function curve_fit(model, jacobian_model, AbstractArray, ydataAbstractArray, p0; kwargs...)
    if lmfit(f, g, p0, []; kwargs...)
    end
end

model = xdata = ydata = p0 = function jacobian_model end
curve_fit(model, jacobian_model, xdata, ydata, p0; maxIter = 1, avv! = !, lambda = 0)

Using Julia#master with assertions enabled:

Instruction does not dominate all uses!
  %58 = select i1 %ifelse_cond34, i8 %42, i8 0, !dbg !82
  %value_phi35 = phi i8 [ %58, %L24 ], [ %value_phi12, %post_union_move43 ]
Instruction does not dominate all uses!
  %55 = select i1 %ifelse_cond33, i8 %45, i8 1, !dbg !82
  %value_phi36 = phi i8 [ %55, %L24 ], [ %value_phi, %post_union_move43 ]
Instruction does not dominate all uses!
  %47 = or i1 %46, false, !dbg !79
  %53 = zext i1 %47 to i8, !dbg !82
Instruction does not dominate all uses!
  %45 = select i1 %ifelse_cond31, i8 1, i8 %value_phi27, !dbg !71
  %55 = select i1 %ifelse_cond33, i8 %45, i8 1, !dbg !82
Instruction does not dominate all uses!
  %47 = or i1 %46, false, !dbg !79
  %56 = zext i1 %47 to i8, !dbg !82
Instruction does not dominate all uses!
  %42 = select i1 %ifelse_cond30, i8 0, i8 %value_phi28, !dbg !71
  %58 = select i1 %ifelse_cond34, i8 %42, i8 0, !dbg !82
julia: /source/src/jitlayers.cpp:1223: {anonymous}::OptimizerT::operator()(llvm::orc::ThreadSafeModule, llvm::orc::MaterializationResponsibility&)::<lambda(llvm::Module&)>: Assertion `!verifyModule(M, &errs())' failed.

Bisected to #50312, so @topolarity I guess we're not out of the woods yet.