re PR c++/10968 (If member function implicitly instantiated, explicit instantiation of class fails to instantiate it)

PR c++/10968
        * pt.c (mark_decl_instantiated): Set TREE_SYMBOL_REFERENCED.

[[Split portion of a mixed commit.]]

From-SVN: r67725.2

gcc/cp/pt.c

@@ -9974,6 +9974,9 @@ mark_decl_instantiated (result, extern_p)
        set correctly by tsubst.  */
     TREE_PUBLIC (result) = 1;
 
+  /* This might have been set by an earlier implicit instantiation.  */
+  DECL_COMDAT (result) = 0;
+
   if (! extern_p)
     {
       DECL_INTERFACE_KNOWN (result) = 1;

gcc/testsuite/g++.dg/template/explicit-instantiation2.C

@@ -0,0 +1,6 @@
+// Bug 10968: implicit instantiation overrides explicit instantiation
+// { dg-final { scan-assembler "_Z1fIiET_S0_" } }
+
+template <class T> T f (T t) { return t; }
+inline void g () { f (4); }
+template int f (int);