[clang] [clang] Don't warn on zero literals with -std=c2y (PR #149688)

[A. Jiang via cfe-commits]

================
@@ -44,7 +44,9 @@ static const void *ptr = 0o0;  /* ext-warning {{octal integer literals are a C2y
 #endif
 
 // 0 by itself is not deprecated, of course.
-int k = 0;
+int k1 = 0;
+long k2 = 0l;
+unsigned long long k3 = 0ull;
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frederick-vs-ja wrote:

Let's check them all.
```suggestion
int k1                = 0;
unsigned int k2       = 0u;
long k3               = 0l;
unsigned long k4      = 0ul;
long long k5          = 0ll;
unsigned long long k6 = 0ull;
```

https://github.com/llvm/llvm-project/pull/149688