[llvm] [DataLayout] Move '*AlignElem' structs and enum inside DataLayout (NFC) (PR #103723)

[Nikita Popov via llvm-commits]

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@@ -159,16 +146,19 @@ class DataLayout {
   /// well-defined bitwise representation.
   SmallVector<unsigned, 8> NonIntegralAddressSpaces;
 
-  /// Attempts to set the alignment of the given type. Returns an error
-  /// description on failure.
-  Error setAlignment(AlignTypeEnum AlignType, Align ABIAlign, Align PrefAlign,
-                     uint32_t BitWidth);
+  // Attempts to set the specification for the given type.
+  // Returns an error description on failure.
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nikic wrote:

If you're documenting an item, it should always be a doxygen comment. This can be any kind of class member, but also e.g. a static function in a source file. (Our default doxygen config does not generate private member documentation, but peculiarly it does generate static item docs.)

https://github.com/llvm/llvm-project/pull/103723