[clang] [ARM, AArch64] Fix passing of structures with aligned base classes (PR #135564)

[John McCall via cfe-commits]

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@@ -1302,6 +1302,7 @@ ItaniumRecordLayoutBuilder::LayoutBase(const BaseSubobjectInfo *Base) {
     setSize(std::max(getSize(), Offset + Layout.getSize()));
 
   // Remember max struct/class alignment.
+  UnadjustedAlignment = std::max(UnadjustedAlignment, PreferredBaseAlign);
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rjmccall wrote:

I think it would be better to get that testing in this patch; it really should've been part of the original composite alignment patch, because the fact that some targets explicitly don't use it is a major aspect of the work.

https://github.com/llvm/llvm-project/pull/135564