[clang-tools-extra] [clang-tidy] Enhance modernize-use-starts-ends-with to handle substr patterns (PR #116033)

[Nicolas van Kempen via cfe-commits]

================
@@ -171,10 +171,24 @@ void UseStartsEndsWithCheck::registerMatchers(MatchFinder *Finder) {
                              hasRHS(lengthExprForStringNode("needle")))))
           .bind("expr"),
       this);
+      Finder->addMatcher(
----------------
nicovank wrote:

This needs `clang-format`, not sure why the CI didn't catch it, maybe something to do with it only trying to format the diff and not the whole file.
```
clang-format -i clang-tools-extra/clang-tidy/modernize/UseStartsEndsWithCheck.cpp
```

https://github.com/llvm/llvm-project/pull/116033