Go patch committed: Correct grammar in error message

[Ian Lance Taylor via Gcc-patches]

This patch to the Go frontend corrects the grammar in an error
message.  Noticed while looking at https://golang.org/issue/43200.
Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu.  Committed
to mainline.

Ian

5aba02667113fbe43d74c37724f29868f098dd1c
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index a28294c594f..6567db167a2 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-10d3dd939d4cea7f40b76f8ff82c16aa12c01188
+526037336231593939a517b7c0b2892d413adb40
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/statements.cc b/gcc/go/gofrontend/statements.cc
index af82f36bc43..398b8fd82f2 100644
--- a/gcc/go/gofrontend/statements.cc
+++ b/gcc/go/gofrontend/statements.cc
@@ -4538,7 +4538,7 @@ Switch_statement::do_lower(Gogo*, Named_object*, Block* 
enclosing,
                                              Type::make_nil_type(), NULL))
     {
       go_error_at(this->val_->location(),
-                 "cannot switch on value whose type that may not be compared");
+                 "cannot switch on value whose type may not be compared");
       return Statement::make_error_statement(loc);
     }