Properly parse a postfix expression following a Boolean literal. Fixes PR34273.

Patch by Nicolas Lesser.

llvm-svn: 314463
diff --git a/clang/test/Parser/cxx-bool.cpp b/clang/test/Parser/cxx-bool.cpp
index a8a161e..21591d1 100644
--- a/clang/test/Parser/cxx-bool.cpp
+++ b/clang/test/Parser/cxx-bool.cpp
@@ -1,4 +1,11 @@
-// RUN: %clang_cc1 -fsyntax-only %s
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// expected-no-diagnostics
 
 bool a = true;
 bool b = false;
+
+namespace pr34273 {
+  char c = "clang"[true];
+  char d = true["clang"];
+}
+