[AST] Get field size in chars rather than bits in RecordLayoutBuilder.

In D79719, LayoutField was refactored to fetch the size of field
types in bits and then convert to chars, rather than fetching
them in chars directly. This is not ideal, since it makes the
calculations char size dependent, and breaks for sizes that
are not a multiple of the char size.

This patch changes it to use getTypeInfoInChars instead of
getTypeInfo.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D85191

Author: bevin-hansson

clang/lib/AST/RecordLayoutBuilder.cpp

@@ -1838,14 +1838,13 @@ void ItaniumRecordLayoutBuilder::LayoutField(const FieldDecl *D,
   CharUnits EffectiveFieldSize;
 
   auto setDeclInfo = [&](bool IsIncompleteArrayType) {
-    TypeInfo TI = Context.getTypeInfo(D->getType());
-    FieldAlign = Context.toCharUnitsFromBits(TI.Align);
+    auto TI = Context.getTypeInfoInChars(D->getType());
+    FieldAlign = TI.second;
     // Flexible array members don't have any size, but they have to be
     // aligned appropriately for their element type.
     EffectiveFieldSize = FieldSize =
-        IsIncompleteArrayType ? CharUnits::Zero()
-                              : Context.toCharUnitsFromBits(TI.Width);
-    AlignIsRequired = TI.AlignIsRequired;
+        IsIncompleteArrayType ? CharUnits::Zero() : TI.first;
+    AlignIsRequired = Context.getTypeInfo(D->getType()).AlignIsRequired;
   };
 
   if (D->getType()->isIncompleteArrayType()) {