[clang-tools-extra] [clang-tidy] Adds do-while support to performance-inefficient-string-concatenation (PR #186607)

[Victor Chernyakin via cfe-commits]

================
@@ -55,5 +55,5 @@ Options
 
 .. option:: StrictMode
 
-   When `false`, the check will only check the string usage in ``while``, ``for``
+   When `false`, the check will only check the string usage in ``while``, ``do-while``, ``for``
    and ``for-range`` statements. Default is `false`.
----------------
localspook wrote:

Instead of listing out all the loop types, maybe we could just say
```suggestion
   When `false`, the check will only warn on inefficient string usage inside loops.
   Default is `false`.
```

https://github.com/llvm/llvm-project/pull/186607