fix clang compatiblity when building with gcc

[fran6co]

Fixes #301

Describe your changes
Just moves calls from header to source

Testing performed
Built with vcpkg and then linked used clang

[RMGiroux]

Thanks @fran6co. What issue is this fixing? We don't see a problem with the inline version of that code in our internal tests against clang.

[fran6co]

This fixes what #301 describes, for some reason the clang and the gcc codes are different so if I compile bde with gcc (like it does with vcpkg on linux) and then I have a project using clang the 2 implementations are going to be different and create the undefined error mentioned in the issue above

[fran6co]

if you build with clang all the way, then there is no problem

[RMGiroux]

Ah, I missed the "Fixes #301" comment in your initial PR, my apologies. We'll take a look at this, thanks.

[RMGiroux]

This is being tracked in internal ticket 181481200