[clang-format] Handle comments below r_brace in RemoveBracesLLVM

[owenpan]

Summary

If a closing brace is followed by a non-trailing comment, the newline before the closing brace must also be removed.

clang/lib/Format/Format.cpp

for (AnnotatedLine *Line : Lines) {
         continue;
       for (FormatToken *Token = Line->First; Token && !Token->Finalized;
            Token = Token->Next) {
         if (!Token->Optional)
           continue;
         assert(Token->isOneOf(tok::l_brace, tok::r_brace));
         assert(Token->Next || Token == Line->Last);
         const auto Start =
-            Token == Line->Last || (Token->Next->is(tok::kw_else) &&
-                                    Token->Next->NewlinesBefore > 0)
+            Token == Line->Last ||
+                    (Token->Next->isOneOf(tok::kw_else, tok::comment) &&
                 ? Token->WhitespaceRange.getBegin()
                 : Token->Tok.getLocation();
         const auto Range =
             CharSourceRange::getCharRange(Start, Token->Tok.getEndLoc());
         cantFail(Result.add(tooling::Replacement(SourceMgr, Range, "")));
       }
     }
   }

clang/unittests/Format/FormatTest.cpp

verifyFormat("if (a)\n"
                "  foo();\n"
                "}\n"
                "else\n"
                "{\n"
                "  bar();\n"
                "}",
                Style);
 
+  verifyFormat("if (a)\n"
+               "  foo();\n"
+               "// comment\n"
+               "else\n"
+               "  bar();",
+               "if (a) {\n"
+               "  foo();\n"
+               "}\n"
+               "// comment\n"
+               "else {\n"
+               "  bar();\n"
+               "}",
+               Style);
+
   verifyFormat("if (a) {\n"
                "Label:\n"
                "}",
                Style);
 
   verifyFormat("if (a) {\n"
                "Label:\n"
                "  f();\n"