Fix DAC layout in checked builds (#35542)

src/coreclr/src/inc/sstring.h

@@ -809,6 +809,7 @@ template <COUNT_T MEMSIZE>
 class EMPTY_BASES_DECL InlineSString : public SString
 {
 private:
+    DAC_ALIGNAS(SString)
     BYTE m_inline[SBUFFER_PADDED_SIZE(MEMSIZE)];
 
 public:
@@ -991,6 +992,7 @@ template <COUNT_T MEMSIZE>
 class EMPTY_BASES_DECL ScratchBuffer : public SString::AbstractScratchBuffer
 {
   private:
+    DAC_ALIGNAS(::SString::AbstractScratchBuffer)
     BYTE m_inline[MEMSIZE];
 
   public:

src/coreclr/src/inc/utilcode.h

@@ -2573,6 +2573,7 @@ template <class MemMgr>
 class CHashTableAndData : public CHashTable
 {
 public:
+    DAC_ALIGNAS(CHashTable)
     ULONG      m_iFree;                // Index into m_pcEntries[] of next available slot
     ULONG      m_iEntries;             // size of m_pcEntries[]