These days, most compilers can perform inlining at link time, as well as compile time. If your function is likely to benefit from inlining, then the Link Time optimizer is likely to do just that.
By the time the linker gets to it, not much about the inline status of compiler output is available, except that the compiler will flag certain objects as being collectible, for instance because an inline function or class template instance appears in multiple compilation units, or it should raise an error when multiple symbols share a name, such as the main function being defined twice. None of this has influence on the actual code it will generate.