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

[Sergei Barannikov via llvm-commits]

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@@ -135,19 +115,26 @@ class DataLayout {
   // FIXME: `unsigned char` truncates the value parsed by `parseSpecifier`.
   SmallVector<unsigned char, 8> LegalIntWidths;
 
+  // Primitive type specifier.
+  enum class PrimitiveSpecifier {
+    Integer = 'i',
+    Float = 'f',
+    Vector = 'v',
+    // TODO: Aggregates are not primitives. This should be separated.
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s-barannikov wrote:

I was hoping to to eliminate this enum member in observable future, but I'll rename to TypeSpecifier for now.

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