clang-format: Fix bug in handling of single-column lists.

Members that are themselves wrapped in fake parentheses would lead to
AvoidBinPacking be set on the wrong ParenState.

After:
  vector<int> aaaa = {
      aaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
      aaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
      aaaaaa.aaaaaaa,
      aaaaaa.aaaaaaa,
      aaaaaa.aaaaaaa,
      aaaaaa.aaaaaaa,
  };

Before we were falling back to bin-packing these.

llvm-svn: 290259
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 27c946e..75d352b 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -6800,6 +6800,14 @@
                "    aaaaaaaa,\n"
                "    aaaaaaaaaaaaaaaaaaaaaaaaaaa};",
                getLLVMStyleWithColumns(30));
+  verifyFormat("vector<int> aaaa = {\n"
+               "    aaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,\n"
+               "    aaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,\n"
+               "    aaaaaa.aaaaaaa,\n"
+               "    aaaaaa.aaaaaaa,\n"
+               "    aaaaaa.aaaaaaa,\n"
+               "    aaaaaa.aaaaaaa,\n"
+               "};");
 }
 
 TEST_F(FormatTest, PullTrivialFunctionDefinitionsIntoSingleLine) {