RDAT: Revert default to MaxRecordSize for tables (microsoft#4682)

On second thought, it's safer to default to the initial version, letting
code that writes to RDAT set strides for newer record versions it actually
uses, rather than breaking RDAT writing code at runtime when versioned
updates are added to the structures.

Author: tex3d

include/dxc/DxilRDATBuilder/DxilRDATBuilder.h

@@ -47,7 +47,7 @@ class DxilRDATBuilder {
     if (!*tablePtr) {
       m_Parts.emplace_back(llvm::make_unique<RDATTable>());
       *tablePtr = reinterpret_cast<RDATTable *>(m_Parts.back().get());
-      (*tablePtr)->SetRecordStride(RDAT::RecordTraits<T>::MaxRecordSize());
+      (*tablePtr)->SetRecordStride(sizeof(T));
       (*tablePtr)->SetType(RDAT::RecordTraits<T>::PartType());
       (*tablePtr)->SetDeduplication(m_bRecordDeduplicationEnabled);
     }