Align a multiline string literal with the first part.

Before:
  #define A(X)          \
    "aaaaa" #X "bbbbbb" \
               "ccccc"

After:
  #define A(X)          \
    "aaaaa" #X "bbbbbb" \
    "ccccc"

llvm-svn: 181732
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 9624ac9..697cc53 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -2231,6 +2231,14 @@
       "#define LL_FORMAT \"ll\"\n"
       "printf(\"aaaaa: %d, bbbbbb: %\" LL_FORMAT \"d, cccccccc: %\" LL_FORMAT\n"
       "       \"d, ddddddddd: %\" LL_FORMAT \"d\");");
+
+  verifyFormat("#define A(X)          \\\n"
+               "  \"aaaaa\" #X \"bbbbbb\" \\\n"
+               "  \"ccccc\"",
+               getLLVMStyleWithColumns(23));
+  verifyFormat("#define A \"def\"\n"
+               "f(\"abc\" A \"ghi\"\n"
+               "  \"jkl\");");
 }
 
 TEST_F(FormatTest, AlignsPipes) {