[OpenMP][OMPIRBuilder] Fix LLVM IR codegen for collapsed device loop (#78708)

When we generate the loop body function, we need to be sure, that all
original loop counters are replaced by the new counter.

We need to save all items which use the original loop counter and then
perform replacement of the original loop counter. If we don't do it,
there is a risk that some values are not updated.

GitOrigin-RevId: 21199f9842dffa4f34b38101195c6f57d1bd4630
1 file changed