Go patch committed: Avoid ICE on invalid

[Ian Lance Taylor]

This patch from Rémy Oudompheng avoids an ICE on invalid in the Go
frontend.  Bootstrapped on x86_64-unknown-linux-gnu.  Committed to
mainline and 4.7 branch.

Ian


diff -r c1a1b9b5894b go/expressions.cc
--- a/go/expressions.cc	Wed Mar 28 15:20:12 2012 -0700
+++ b/go/expressions.cc	Wed Mar 28 15:24:08 2012 -0700
@@ -10577,7 +10577,8 @@
 tree
 Interface_field_reference_expression::do_get_tree(Translate_context*)
 {
-  go_unreachable();
+  error_at(this->location(), "reference to method other than calling it");
+  return error_mark_node;
 }
 
 // Dump ast representation for an interface field reference.