Function rustc_const_eval::const_eval::eval_queries::op_to_const

pub(super) fn op_to_const<'tcx>(
    ecx: &InterpCx<'_, 'tcx, CompileTimeInterpreter<'_, 'tcx>>,
    op: &OpTy<'tcx>,
    for_diagnostics: bool
) -> ConstValue<'tcx>

This function converts an interpreter value into a MIR constant.

The for_diagnostics flag turns the usual rules for returning ConstValue::Scalar into a best-effort attempt. This is not okay for use in const-eval sine it breaks invariants rustc relies on, but it is okay for diagnostics which will just give up gracefully when they encounter an Indirect they cannot handle.