[clang-format] Apply BAS_AlwaysBreak to C++11 braced lists

[owenpan]

Summary

See PR18455 and this message.

[MyDeveloperDay]

Thank you for this patch, i've seen a number of PRs raise to this effect.. this looks to be a great start in this area

LGTM

clang/lib/Format/ContinuationIndenter.cpp

if (Current.is(TT_SelectorName) &&
     else
       State.Stack.back().ColonPos = FirstColonPos;
   }
 
   // In "AlwaysBreak" mode, enforce wrapping directly after the parenthesis by
   // disallowing any further line breaks if there is no line break after the
   // opening parenthesis. Don't break if it doesn't conserve columns.
   if (Style.AlignAfterOpenBracket == FormatStyle::BAS_AlwaysBreak &&
-      Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) &&
+      (Previous.isOneOf(tok::l_paren, TT_TemplateOpener, tok::l_square) ||
+       (Previous.is(tok::l_brace) && Previous.BlockKind != BK_Block &&
+        Style.Cpp11BracedListStyle)) &&
       State.Column > getNewLineColumn(State) &&
       (!Previous.Previous || !Previous.Previous->isOneOf(
                                  tok::kw_for, tok::kw_while, tok::kw_switch)) &&
       // Don't do this for simple (no expressions) one-argument function calls
       // as that feels like needlessly wasting whitespace, e.g.:
       //
       //   caaaaaaaaaaaall(
       //       caaaaaaaaaaaall(

clang/unittests/Format/FormatTest.cpp

TEST_F(FormatTest, LayoutCxx11BraceInitializers) {
   verifyFormat(
       "const Aaaaaa aaaaa = {\n"
       "    aaaaa,  bbbbb,  ccccc,  ddddd,  eeeee,  ffffff, ggggg, hhhhhh,\n"
       "    iiiiii, jjjjjj, kkkkkk, aaaaa,  bbbbb,  ccccc,  ddddd, eeeee,\n"
       "    ffffff, ggggg,  hhhhhh, iiiiii, jjjjjj, kkkkkk,\n"
       "};",
       NoBinPacking);
 
+  NoBinPacking.AlignAfterOpenBracket = FormatStyle::BAS_AlwaysBreak;
+  EXPECT_EQ("static uint8 CddDp83848Reg[] = {\n"
+            "    CDDDP83848_BMCR_REGISTER,\n"
+            "    CDDDP83848_BMSR_REGISTER,\n"
+            "    CDDDP83848_RBR_REGISTER};",
+            format("static uint8 CddDp83848Reg[] = {CDDDP83848_BMCR_REGISTER,\n"
+                   "                                CDDDP83848_BMSR_REGISTER,\n"
+                   "                                CDDDP83848_RBR_REGISTER};",
+                   NoBinPacking));
+
   // FIXME: The alignment of these trailing comments might be bad. Then again,
   // this might be utterly useless in real code.
   verifyFormat("Constructor::Constructor()\n"
                "    : some_value{         //\n"
                "                 aaaaaaa, //\n"
                "                 bbbbbbb} {}");
 
   // In braced lists, the first comment is always assumed to belong to the