clang-format: Fix template declaration line breaking with comment.

Before, clang-format would always insert a linebreak before the comment
in code like:
  template <typename T> // T can be A, B or C.
  struct S {};

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192297 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 3714088..560e65e 100644
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -178,7 +178,8 @@
       State.Stack.back().BreakBeforeParameter)
     return true;
   if ((Current.Type == TT_CtorInitializerColon ||
-       (Previous.ClosesTemplateDeclaration && State.ParenLevel == 0)))
+       (Previous.ClosesTemplateDeclaration && State.ParenLevel == 0 &&
+        !Current.isTrailingComment())))
     return true;
 
   if ((Current.Type == TT_StartOfName || Current.is(tok::kw_operator)) &&