[clang] [clang-format] Fix a TableGen crash on comment after l_paren (PR #124380)

[Hirofumi Nakamura via cfe-commits]

================
@@ -101,6 +101,9 @@ TEST_F(FormatTestTableGen, BangOperators) {
                "                                  \"zerozero\",\n"
                "                                  true:  // default\n"
                "                                  \"positivepositive\");\n"
+               "  let Foo = !cond(\n"
----------------
hnakamura5 wrote:

How about describing in name?

```suggestion
               "  let CondOpeCommentAfterLParen = !cond(\n"
```

https://github.com/llvm/llvm-project/pull/124380