[clang-format] Never remove braces in macro definitions

Fixes #56559.

Differential Revision: https://reviews.llvm.org/D129921

clang/lib/Format/UnwrappedLineParser.cpp

@@ -539,7 +539,7 @@ bool UnwrappedLineParser::parseLevel(const FormatToken *OpeningBrace,
       break;
     case tok::r_brace:
       if (OpeningBrace) {
-        if (!Style.RemoveBracesLLVM ||
+        if (!Style.RemoveBracesLLVM || Line->InPPDirective ||
             !OpeningBrace->isOneOf(TT_ControlStatementLBrace, TT_ElseLBrace)) {
           return false;
         }

clang/unittests/Format/FormatTest.cpp

@@ -25803,6 +25803,13 @@ TEST_F(FormatTest, RemoveBraces) {
 
   Style.ColumnLimit = 20;
 
+  verifyFormat("int i;\n"
+               "#define FOO(a, b)  \\\n"
+               "  while (a) {      \\\n"
+               "    b;             \\\n"
+               "  }",
+               Style);
+
   verifyFormat("int ab = [](int i) {\n"
                "  if (i > 0) {\n"
                "    i = 12345678 -\n"