compiler: Don't create a closure if not needed.

From-SVN: r187897

gcc/go/gofrontend/expressions.cc

@@ -1312,30 +1312,18 @@ Func_expression::do_get_tree(Translate_context* context)
 	     && TREE_CODE(TREE_OPERAND(fnaddr, 0)) == FUNCTION_DECL);
   TREE_ADDRESSABLE(TREE_OPERAND(fnaddr, 0)) = 1;
 
-  // For a normal non-nested function call, that is all we have to do.
-  if (!this->function_->is_function()
-      || this->function_->func_value()->enclosing() == NULL)
-    {
-      go_assert(this->closure_ == NULL);
-      return fnaddr;
-    }
+  // If there is no closure, that is all have to do.
+  if (this->closure_ == NULL)
+    return fnaddr;
 
-  // For a nested function call, we have to always allocate a
-  // trampoline.  If we don't always allocate, then closures will not
-  // be reliably distinct.
-  Expression* closure = this->closure_;
-  tree closure_tree;
-  if (closure == NULL)
-    closure_tree = null_pointer_node;
-  else
-    {
-      // Get the value of the closure.  This will be a pointer to
-      // space allocated on the heap.
-      closure_tree = closure->get_tree(context);
-      if (closure_tree == error_mark_node)
-	return error_mark_node;
-      go_assert(POINTER_TYPE_P(TREE_TYPE(closure_tree)));
-    }
+  go_assert(this->function_->func_value()->enclosing() != NULL);
+
+  // Get the value of the closure.  This will be a pointer to space
+  // allocated on the heap.
+  tree closure_tree = this->closure_->get_tree(context);
+  if (closure_tree == error_mark_node)
+    return error_mark_node;
+  go_assert(POINTER_TYPE_P(TREE_TYPE(closure_tree)));
 
   // Now we need to build some code on the heap.  This code will load
   // the static chain pointer with the closure and then jump to the