Implement a %plural modifier for complex plural forms in diagnostics. Use it in the overload diagnostics.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59871 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/overloaded-operator.cpp b/test/SemaCXX/overloaded-operator.cpp
index 98f0bb0..bc47383 100644
--- a/test/SemaCXX/overloaded-operator.cpp
+++ b/test/SemaCXX/overloaded-operator.cpp
@@ -170,5 +170,5 @@
 void test_arrow(Arrow1 a1, Arrow2 a2, const Arrow2 a3) {
   int &i1 = a1->m;
   int &i2 = a2->m;
-  a3->m; // expected-error{{no viable overloaded 'operator->'; candidates are}}
+  a3->m; // expected-error{{no viable overloaded 'operator->'; candidate is}}
 }