compiler, runtime: don't pass size to __go_new

There is no reason to pass the size to __go_new, as the type
descriptor includes the size anyhow.  This makes the function
correspond to the Go 1.8 function runtime.newobject, which is what we
will use when we update to the Go 1.8 memory allocator.

Change-Id: I8817a5f204beaeac7b877d1e7a207a1893c1922f
Reviewed-on: https://go-review.googlesource.com/41080
Reviewed-by: Than McIntosh <thanm@google.com>
3 files changed