[non-Cocoa] Add a new AuxiliaryProcessMainBase class for auxiliary processes without singleton() non-Cocoa ports are using AuxiliaryProcessMain as entry point utility. AuxiliaryProcessMain supports both kinds of auxiliary processes with and without singleton() method by using initializeAuxiliaryProcess template function. However, initializeAuxiliaryProcess looks similar code. They can share more code.
Created attachment 417592 [details] Patch
Committed r271563: <https://trac.webkit.org/changeset/271563>
<rdar://problem/73300939>