[clang] [clang][Interp] Decay arrays to the first element (PR #72660)

[Aaron Ballman via cfe-commits]

================
@@ -27,6 +27,9 @@ static_assert(foo[2][3] == &m, "");
 static_assert(foo[2][4] == nullptr, "");
 
 
+const int SomeInt[] = {1};
+int getSomeInt() { return *SomeInt; }
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AaronBallman wrote:

```suggestion
constexpr int SomeInt[] = {1};
constexpr int getSomeInt() { return *SomeInt; }

static_assert(getSomeInt() == 1);
```
so we're testing the decayed pointer.

https://github.com/llvm/llvm-project/pull/72660