clang-format: Don't force linebreak between return and multiline string.

This looks ugly and leads to llvm.org/PR17590.

Before (with AlwaysBreakBeforeMultilineStrings):
  return
      "aaaa"
      "bbbb";

After:
  return "aaaa"
         "bbbb";

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192984 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 15d05f5..6bcf44c 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -5590,6 +5590,12 @@
                    "aaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaa "
                    "aaaaaaaaaaaaaaaaaaaaaa\");",
                    getGoogleStyle()));
+  EXPECT_EQ("return \"aaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaa \"\n"
+            "       \"aaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaa\";",
+            format("return \"aaaaaaaaaaaaaaaaaaaaaa "
+                   "aaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaa "
+                   "aaaaaaaaaaaaaaaaaaaaaa\";",
+                   getGoogleStyle()));
   EXPECT_EQ("llvm::outs() << \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \"\n"
             "                \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\";",
             format("llvm::outs() << "