[clang-tools-extra] [clang-tidy] fix an edge case in readability-implicit-bool-conversion (PR #186234)

[Zeyi Xu via cfe-commits]

================
@@ -3,11 +3,14 @@
 // RUN:  {readability-implicit-bool-conversion.AllowIntegerConditions: true, \
 // RUN:   readability-implicit-bool-conversion.AllowPointerConditions: true}}'
 
+namespace std { struct string { string(const char*); }; }
----------------
zeyi2 wrote:

```suggestion
#include <string>
```

We now have universal mock headers, so you don't have to do it yourself :)

https://github.com/llvm/llvm-project/pull/186234