Check in a pristine copy of GCC 4.8.1.

The copy of GCC that we use for Android is still not working for
mingw. Rather than finding all the differences that have crept into
our GCC, just check in a copy from
ftp://ftp.gnu.org/gnu/gcc/gcc-4.9.3/gcc-4.8.1.tar.bz2.

GCC 4.8.1 was chosen because it is what we have been using for mingw
thus far, and the emulator doesn't yet work when upgrading to 4.9.

Bug: http://b/26523949
Change-Id: Iedc0f05243d4332cc27ccd46b8a4b203c88dcaa3

1 files changed, 45 insertions, 0 deletions

diff --git a/gcc-4.8.1/libgo/runtime/go-assert-interface.c b/gcc-4.8.1/libgo/runtime/go-assert-interface.c
new file mode 100644
index 000000000..2510f9aef
--- /dev/null
+++ b/gcc-4.8.1/libgo/runtime/go-assert-interface.c
@@ -0,0 +1,45 @@
+/* go-assert-interface.c -- interface type assertion for Go.
+
+   Copyright 2010 The Go Authors. All rights reserved.
+   Use of this source code is governed by a BSD-style
+   license that can be found in the LICENSE file.  */
+
+#include "runtime.h"
+#include "go-alloc.h"
+#include "go-assert.h"
+#include "go-panic.h"
+#include "go-type.h"
+#include "interface.h"
+
+/* This is called by the compiler to implement a type assertion from
+   one interface type to another.  This returns the value that should
+   go in the first field of the result tuple.  The result may be an
+   empty or a non-empty interface.  */
+
+const void *
+__go_assert_interface (const struct __go_type_descriptor *lhs_descriptor,
+		       const struct __go_type_descriptor *rhs_descriptor)
+{
+  const struct __go_interface_type *lhs_interface;
+
+  if (rhs_descriptor == NULL)
+    {
+      struct __go_empty_interface panic_arg;
+
+      /* A type assertion is not permitted with a nil interface.  */
+
+      runtime_newTypeAssertionError (NULL, NULL, lhs_descriptor->__reflection,
+				     NULL, &panic_arg);
+      __go_panic (panic_arg);
+    }
+
+  /* A type assertion to an empty interface just returns the object
+     descriptor.  */
+
+  __go_assert (lhs_descriptor->__code == GO_INTERFACE);
+  lhs_interface = (const struct __go_interface_type *) lhs_descriptor;
+  if (lhs_interface->__methods.__count == 0)
+    return rhs_descriptor;
+
+  return __go_convert_interface_2 (lhs_descriptor, rhs_descriptor, 0);
+}