[clang-format] Fix parsing of <>-style proto options

[krasimir]

Summary

This patch fixes the parsing of proto option fields like option op = <...>.
Previously the parser did not enter the right code path inside the angle braces,
causing the contents to be split into several unwrapped lines inside.

cfe/trunk/lib/Format/UnwrappedLineParser.cpp

case tok::l_paren:
       break;
     case tok::l_brace:
       // Assume there are no blocks inside a braced init list apart
       // from the ones we explicitly parse out (like lambdas).
       FormatTok->BlockKind = BK_BracedInit;
       nextToken();
       parseBracedList();
       break;
+    case tok::less:
+      if (Style.Language == FormatStyle::LK_Proto) {
+        nextToken();
+        parseBracedList(/*ContinueOnSemicolons=*/false,
+                        /*ClosingBraceKind=*/tok::greater);
+      } else {
+        nextToken();
+      }
+      break;
     case tok::semi:
       // JavaScript (or more precisely TypeScript) can have semicolons in braced
       // lists (in so-called TypeMemberLists). Thus, the semicolon cannot be
       // used for error recovery if we have otherwise determined that this is
       // a braced list.
       if (Style.Language == FormatStyle::LK_JavaScript) {
         nextToken();
         break;

cfe/trunk/unittests/Format/FormatTestProto.cpp

verifyFormat("option (MyProto.options) = <\n"
                "      field_E: 5\n"
                "    >\n"
                "    msg_field <field_A: 1 field_B: 2 field_C: 3 field_D: 4>\n"
                "    field_e: OK\n"
                "    field_f: OK\n"
                "  }\n"
                "  field_g: OK\n"
                ">;");
+
+  verifyFormat("option (MyProto.options) = <\n"
+               "  data1 <key1: value1>\n"
+               "  data2 {key2: value2}\n"
+               ">;");
 }
 
 TEST_F(FormatTestProto, FormatsService) {
   verifyFormat("service SearchService {\n"
                "  rpc Search(SearchRequest) returns (SearchResponse) {\n"
                "    option foo = true;\n"
                "  }\n"
                "};");