code review 198770044: compiler, reflect, runtime: Use static chain for closures.

compiler, reflect, runtime: Use static chain for closures.

Change from using __go_set_closure to passing the closure
value in the static chain field.  Uses new backend support for
setting the closure chain in a call from C via
__builtin_call_with_static_chain.  Uses new support in libffi
for Go closures.

The old architecture specific support for reflect.MakeFunc is
removed, replaced by the libffi support.

All work done by Richard Henderson.

[iant, 2015-01-16 21:28:19]

Hello iant@golang.org (cc: gofrontend-dev@googlegroups.com),

I'd like you to review this change to
https://iant%40golang.org@code.google.com/p/gofrontend

[iant, 2015-01-16 21:28:25]

*** Submitted as
https://code.google.com/p/gofrontend/source/detail?r=bb70e852004f ***

compiler, reflect, runtime: Use static chain for closures.

Change from using __go_set_closure to passing the closure
value in the static chain field.  Uses new backend support for
setting the closure chain in a call from C via
__builtin_call_with_static_chain.  Uses new support in libffi
for Go closures.

The old architecture specific support for reflect.MakeFunc is
removed, replaced by the libffi support.

All work done by Richard Henderson.

R=iant
CC=gofrontend-dev
https://codereview.appspot.com/198770044