Implements breaking string literals at slashes.

We now break at a slash if we do not find a space to break on.

Also fixes a bug where we would go over the limit when breaking the
second line.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176350 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 8cc8168..8b1f69a 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -3045,9 +3045,15 @@
 
   EXPECT_EQ(
       "\"splitmea\"\n"
-      "\"trandompo\"\n"
-      "\"int\"",
+      "\"trandomp\"\n"
+      "\"oint\"",
       format("\"splitmeatrandompoint\"", getLLVMStyleWithColumns(10)));
+
+  EXPECT_EQ(
+      "\"split/\"\n"
+      "\"pathat/\"\n"
+      "\"slashes\"",
+      format("\"split/pathat/slashes\"", getLLVMStyleWithColumns(10)));
 }
 
 } // end namespace tooling