[clang] [clang-format] Add IndentPPDirectives Leave option (PR #139750)

[Björn Schäpers via cfe-commits]

================
@@ -1142,7 +1144,8 @@ void UnwrappedLineParser::parsePPEndIf() {
   // If the #endif of a potential include guard is the last thing in the file,
   // then we found an include guard.
   if (IncludeGuard == IG_Defined && PPBranchLevel == -1 && Tokens->isEOF() &&
-      Style.IndentPPDirectives != FormatStyle::PPDIS_None) {
+      !(Style.IndentPPDirectives == FormatStyle::PPDIS_None ||
+        Style.IndentPPDirectives == FormatStyle::PPDIS_Leave)) {
----------------
HazardyKnusperkeks wrote:

```suggestion
      Style.IndentPPDirectives != FormatStyle::PPDIS_None &&
      Style.IndentPPDirectives != FormatStyle::PPDIS_Leave) {
```

https://github.com/llvm/llvm-project/pull/139750