Rollup merge of #156319 - bjorn3:eii_dylib_require_def, r=jdonszelmann

Require EIIs to be defined when we compile a rust dylib

The linker will complain about undefined symbols otherwise and on object file formats with two level namespaces (Mach-O and PE/COFF) it is required to know which dylib a symbol will be imported from when linking a dylib or executable.

r? @jdonszelmann