[clang-format] Handle wrapped else for RemoveBracesLLVM

[owenpan]

Summary

Removes the newline before the right brace that's followed by an else on the next line.

[curdeius]

LGTM

clang/lib/Format/Format.cpp

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

clang/unittests/Format/FormatTest.cpp

verifyFormat("int abs = [](int i) {\n"
                "int abs = [](int i) {\n"
                "  if (i >= 0) {\n"
                "    return i;\n"
                "  }\n"
                "  return -i;\n"
                "};",
                Style);
 
+  verifyFormat("if (a)\n"
+               "  foo();\n"
+               "else\n"
+               "  bar();",
+               "if (a)\n"
+               "{\n"
+               "  foo();\n"
+               "}\n"
+               "else\n"
+               "{\n"
+               "  bar();\n"
+               "}",
+               Style);
+
   // FIXME: See https://github.com/llvm/llvm-project/issues/53543.
 #if 0
   Style.ColumnLimit = 65;
 
   verifyFormat("if (condition) {\n"
                "  ff(Indices,\n"
                "     [&](unsigned LHSI, unsigned RHSI) { return true; });\n"
                "} else {\n"