Better support for multiline string literals (including C++11 raw string literals).

Summary:
Calculate characters in the first and the last line correctly so that
we only break before the literal when needed.

Reviewers: djasper

Reviewed By: djasper

CC: cfe-commits, klimek

Differential Revision: http://llvm-reviews.chandlerc.com/D1544

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189595 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index b634bbd..ce837d4 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -1024,8 +1024,7 @@
     Current->CanBreakBefore =
         Current->MustBreakBefore || canBreakBefore(Line, *Current);
     if (Current->MustBreakBefore ||
-        (Current->is(tok::string_literal) &&
-         Current->TokenText.find("\\\n") != StringRef::npos))
+        (Current->is(tok::string_literal) && Current->IsMultiline))
       Current->TotalLength = Current->Previous->TotalLength + Style.ColumnLimit;
     else
       Current->TotalLength = Current->Previous->TotalLength +