go-gcc.cc (Gcc_backend::fill_in_struct): Mark struct types as using structural equality.

	* go-gcc.cc (Gcc_backend::fill_in_struct): Mark struct types as
	using structural equality.

From-SVN: r257357

gcc/go/ChangeLog

+2018-02-03  Ian Lance Taylor  <iant@golang.org>
+
+	* go-gcc.cc (Gcc_backend::fill_in_struct): Mark struct types as
+	using structural equality.
+
 2018-02-02  Ian Lance Taylor  <iant@golang.org>
 
 	* go-gcc.cc (Gcc_backend::type_size): Return 0 for

gcc/go/go-gcc.cc

@@ -962,6 +962,13 @@ Gcc_backend::fill_in_struct(Btype* fill,
     }
   TYPE_FIELDS(fill_tree) = field_trees;
   layout_type(fill_tree);
+
+  // Because Go permits converting between named struct types and
+  // equivalent struct types, for which we use VIEW_CONVERT_EXPR, and
+  // because we don't try to maintain TYPE_CANONICAL for struct types,
+  // we need to tell the middle-end to use structural equality.
+  SET_TYPE_STRUCTURAL_EQUALITY(fill_tree);
+
   return fill;
 }