[clang] [analyzer] Unbreak [[clang::suppress]] on checkers without decl-with-issue. (PR #79398)

[Balazs Benics via cfe-commits]

================
@@ -44,7 +47,9 @@ class BugSuppression {
   using CachedRanges =
       llvm::SmallVector<SourceRange, EXPECTED_NUMBER_OF_SUPPRESSIONS>;
 
-  llvm::DenseMap<const Decl *, CachedRanges> CachedSuppressionLocations;
+  llvm::DenseMap<const Decl *, CachedRanges> CachedSuppressionLocations{};
+
+  ASTContext &ACtx;
----------------
steakhal wrote:

```suggestion
  llvm::DenseMap<const Decl *, CachedRanges> CachedSuppressionLocations;

  const ASTContext &ACtx;
```

https://github.com/llvm/llvm-project/pull/79398