[clang] [clang-format] Support of TableGen statements in unwrapped line parser (PR #78846)

[Björn Schäpers via cfe-commits]

================
@@ -2743,6 +2760,14 @@ FormatToken *UnwrappedLineParser::parseIfThenElse(IfStmtKind *IfKind,
     }
   }
 
+  // TableGen's if statement has the form of `if <cond> then { ... }`.
+  if (Style.isTableGen()) {
+    while (!eof() && !(FormatTok->is(Keywords.kw_then))) {
----------------
HazardyKnusperkeks wrote:

```suggestion
    while (!eof() && FormatTok->isNot(Keywords.kw_then)) {
```

https://github.com/llvm/llvm-project/pull/78846