[clang] [clang-format][NFC] Port FormatTestComments to verifyFormat (PR #164310)

[via cfe-commits]

================
@@ -3991,224 +3988,224 @@ TEST_F(FormatTestComments, SpaceAtLineCommentBegin) {
       "//vv will only move\n"
       "//} if the line above does";
----------------
owenca wrote:

```suggestion
      "//} if the line above does");
  constexpr StringRef Code2(
      ...);
  constexpr StringRef Code3(
      ...);
  constexpr StringRef Code4(
      ...);
```
See below.

https://github.com/llvm/llvm-project/pull/164310