[clang] [clang] Implement constexpr heap allocation alignments (PR #174549)

[Timm Baeder via cfe-commits]

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@@ -269,6 +270,18 @@ struct Descriptor final {
   /// Whether variables of this descriptor need their destructor called or not.
   bool hasTrivialDtor() const;
 
+  /// Returns the kind of dynamic allocation source of this block.
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tbaederr wrote:

All of this (and the comments above these functions) seem to indicate that this is a per-block property that only exists for block pointers. 

https://github.com/llvm/llvm-project/pull/174549