[clang] [CIR] Upstream simple function bodies (PR #127674)

[Andy Kaylor via cfe-commits]

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@@ -61,6 +64,13 @@ class CIRGenTypes {
 
   /// Convert a Clang type into a mlir::Type.
   mlir::Type convertType(clang::QualType type);
+
+  /// Convert type T into an mlir::Type. This differs from convertType in that
+  /// it is used to convert to the memory representation for a type. For
+  /// example, the scalar representation for bool is i1, but the memory
+  /// representation is usually i8 or i32, depending on the target.
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andykaylor wrote:

When is the memory type used in ClangIR? Given the target-dependence, it seems like we'd at least want this deferred until the lowering phase.

https://github.com/llvm/llvm-project/pull/127674