Prior to adding the new "expected-no-diagnostics" directive to VerifyDiagnosticConsumer, make the necessary adjustment to 580 test-cases which will henceforth require this new directive.

llvm-svn: 166280
diff --git a/clang/test/Preprocessor/cxx_true.cpp b/clang/test/Preprocessor/cxx_true.cpp
index 5ee2972..39cb349 100644
--- a/clang/test/Preprocessor/cxx_true.cpp
+++ b/clang/test/Preprocessor/cxx_true.cpp
@@ -3,6 +3,7 @@
    RUN: %clang_cc1 -E %s -x c | not grep block
    RUN: %clang_cc1 -E %s -x c++ -verify -Wundef
 */
+// expected-no-diagnostics
 
 #if true
 block_1