[compiler-rt] [SanitizerCommon] add null check for fopen64 interceptor (PR #68760)

[Thurston Dang via llvm-commits]

================
@@ -0,0 +1,8 @@
+// Check that fopen64(NULL, "r") is ok.
+
+// REQUIRES: linux
----------------
thurstond wrote:

The interceptors file defines
```
#define SANITIZER_INTERCEPT_FOPEN64 (SI_GLIBC || SI_SOLARIS32)
```
so `// REQUIRES: glibc` might be a safer bet? (and technically solaris32, but no one will notice). Not all Linux builds will have glibc.


https://github.com/llvm/llvm-project/pull/68760