compiler: fix parsing of composite literals with omitted pointer types

    
    The frontend could parse omitted pointer typess at the end of the
    type, but not in the middle, so code like []*[][]int{{{1}}} failed.
    
    Test case is in https://golang.org/cl/123477.
    
    Fixes golang/go#26340
    
    Reviewed-on: https://go-review.googlesource.com/123479

From-SVN: r262641

gcc/go/gofrontend/MERGE

-267686fd1dffbc03e610e9f17dadb4e72c75f18d
+3f7e72eca3f9221e67c055841d42851aa6a66aff
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

gcc/go/gofrontend/expressions.cc

@@ -13666,6 +13666,7 @@ Composite_literal_expression::do_lower(Gogo* gogo, Named_object* function,
 
   for (int depth = 0; depth < this->depth_; ++depth)
     {
+      type = type->deref();
       if (type->array_type() != NULL)
 	type = type->array_type()->element_type();
       else if (type->map_type() != NULL)