Configure.in tweaking for windows

Good evening all,
I am checking for usefulness of adding another option for Win builders in  
configure.in .

In configure.in, I saw that around line 2750 :
# Check for 64-bit (cross-)compiler to use to build the 64-bit
# version of the Explorer extension (and maybe other small
[SNIP]

AC_MSG_CHECKING([for a x64 compiler and libraries for 64bit ActiveX  
component])
        if test "$CL_X64" = "" -a -f  
"$with_cl_home/atlmfc/lib/amd64/atls.lib"; then

This test occurs after checking if we enabled ATL and/or activex.
If I understand well, LO does not need Activex to build 64-bit shell  
extension, so why searching for atls.lib there (it seems to come from  
Kendy on ee03eb213fa31efb6d5fea16edbeb64dd8b38a9f ) ?

If ATL is needed (only for ?) ActiveX, why do we have 2 options for that  
?either is disabled, we should not even try to search for the compiler, no  
?

Thanks for the reply.
--
Mat M