[IRGen] Don't wait until we find libswiftCore to autolink libobjc.

No intended functionality change.

Swift SVN r29443

Author: jrose-apple

lib/IRGen/GenDecl.cpp

@@ -441,11 +441,11 @@ void IRGenModule::emitSourceFile(SourceFile &SF, unsigned StartElem) {
 
     next->collectLinkLibraries([this](LinkLibrary linkLib) {
       this->addLinkLibrary(linkLib);
-      if (ObjCInterop)
-        if (linkLib.getName().equals("swiftCore"))
-          this->addLinkLibrary(LinkLibrary("objc", LibraryKind::Library));
     });
   });
+
+  if (ObjCInterop)
+    this->addLinkLibrary(LinkLibrary("objc", LibraryKind::Library));
 }
 
 /// Emit a global list, i.e. a global constant array holding all of a