Correct comment Clang C++ use in production.

This was from way-back-when (r82583) when Clang's C++ support wasn't prime-time
yet. Production quality C++ was tested experimentally from r100119 and turned
on by default in r141063.

Patch by Justin Bogner.

llvm-svn: 150148
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index bc571b9..10eec2e 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -65,7 +65,7 @@
     CCCUsePCH(true), SuppressMissingInputWarning(false) {
   if (IsProduction) {
     // In a "production" build, only use clang on architectures we expect to
-    // work, and don't use clang C++.
+    // work.
     //
     // During development its more convenient to always have the driver use
     // clang, but we don't want users to be confused when things don't work, or