Go patch committed: Don't heap allocate non-escaping Bound_method_expression

[Ian Lance Taylor]

This patch to  the Go frontend by Cherry Zhang makes non-escaping
Bound_method_expression not heap allocate.  It stack allocates the
closure when it does not escape.  Bootstrapped on x86_64-pc-linux-gnu.
Committed to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 256406)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-584fdecefce831c3471dbd4857ba0ce0be2b5212
+d5774539b17112d9ce709a1fe722daf68eb8594f
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: gcc/go/gofrontend/expressions.cc
===================================================================
--- gcc/go/gofrontend/expressions.cc    (revision 256406)
+++ gcc/go/gofrontend/expressions.cc    (working copy)
@@ -7030,7 +7030,12 @@ Bound_method_expression::do_flatten(Gogo
   Expression* ret = Expression::make_struct_composite_literal(st, vals, loc);
 
   if (!gogo->compiling_runtime() || gogo->package_name() != "runtime")
-    ret = Expression::make_heap_expression(ret, loc);
+    {
+      ret = Expression::make_heap_expression(ret, loc);
+      Node* n = Node::make_node(this);
+      if ((n->encoding() & ESCAPE_MASK) == Node::ESCAPE_NONE)
+        ret->heap_expression()->set_allocate_on_stack();
+    }
   else
     {
       // When compiling the runtime, method closures do not escape.