patch 8.0.0348: using shadow dir on Mac lack +clipboard

Problem:    When building with a shadow directory on macOS lacks the
            +clipboard feature.
Solution:   Link *.m files, specifically os_macosx.m. (Kazunobu Kuriyama)

Author: brammool

src/Makefile

@@ -2763,7 +2763,7 @@ SHADOWDIR = shadow
 
 shadow:	runtime pixmaps
 	mkdir $(SHADOWDIR)
-	cd $(SHADOWDIR); ln -s ../*.[ch] ../*.in ../*.sh ../*.xs ../*.xbm ../gui_gtk_res.xml ../toolcheck ../proto ../vimtutor ../gvimtutor ../mkinstalldirs .
+	cd $(SHADOWDIR); ln -s ../*.[chm] ../*.in ../*.sh ../*.xs ../*.xbm ../gui_gtk_res.xml ../toolcheck ../proto ../vimtutor ../gvimtutor ../mkinstalldirs .
 	mkdir $(SHADOWDIR)/auto
 	cd $(SHADOWDIR)/auto; ln -s ../../auto/configure .
 	mkdir $(SHADOWDIR)/po

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    348,
 /**/
     347,
 /**/