[clang] [analyzer] Fix crash of StreamChecker when eval calling 'fopen' (PR #100990)

[Balazs Benics via cfe-commits]

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@@ -1766,13 +1770,6 @@ are assumed to succeed.)
    fclose(p);
  }
 
-**Limitations**
-
-The checker does not track the correspondence between integer file descriptors
-and ``FILE *`` pointers. Operations on standard streams like ``stdin`` are not
-treated specially and are therefore often not recognized (because these streams
-are usually not opened explicitly by the program, and are global variables).
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steakhal wrote:

Yea, but I didn't know exactly what it refers to. We could add an example for such a case there. That would help.

https://github.com/llvm/llvm-project/pull/100990