splice problem

Hi all and thank you in advance.
I have problem connected with to functions basic blocks list splice, I
have tried to splice list of basic blocks one function with another
and after delete it, I have replaced all uses of this function with
another, I have even tried splice basic blocks of copy of this
function, but it also does not help, I have got working byte code and
I have compiled it by help llc, problem is in clang, clang throw
exception when works pass "Delete Garbage Collector Information" pass.
best regards Sevak.