Go patch committed: report invalid receiver types

[Ian Lance Taylor]

This patch by Chris Manghane fixes the Go frontend to report invalid
function receiver types as an error rather than crashing.  This fixes
https://golang.org/issue/12324 .  Bootstrapped and ran Go testsuite on
x86_64-unknown-linux-gnu.  Committed to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 227420)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-3f8feb4f905535448833a14e4f5c83f682087749
+672ac2abc52d8bd70cb9fb03dd4a32fdde9c438f
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: gcc/go/gofrontend/gogo.cc
===================================================================
--- gcc/go/gofrontend/gogo.cc   (revision 227299)
+++ gcc/go/gofrontend/gogo.cc   (working copy)
@@ -1818,7 +1818,11 @@ Gogo::start_function(const std::string&
                                                                  function);
            }
          else
-           go_unreachable();
+            {
+              error_at(type->receiver()->location(),
+                       "invalid receiver type (receiver must be a named 
type)");
+              ret = Named_object::make_function(name, NULL, function);
+            }
        }
       this->package_->bindings()->add_method(ret);
     }