Revert 3 unrelated logical changes from SDK modernization commit

Fixes regressions introduced in 5711bf6 that were unrelated to the
SDK modernization goal:

1. Slice.cs: Restore expansion logic to != "doNotExpand" (expand by
   default) instead of == "expanded" (collapsed by default)
2. StackDumper.cpp: Restore deliberate null-pointer dereference SEH
   pattern in DumpStackHere, remove RtlCaptureStackBackTrace import,
   and simplify HandleThrowable format string
3. StackDumperWin64.cpp: Fix GetProcAddress loading of
   SymGetLineFromAddr64 (dead code replaced with actual call)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jasonleenaylor

Src/Common/Controls/DetailControls/Slice.cs

@@ -1130,7 +1130,7 @@ public virtual void GenerateChildren(XmlNode node, XmlNode caller, ICmObject obj
 				//				|| (fUseChildrenOfNode && XmlUtils.GetOptionalAttributeValue(node, "expansion") == "expanded")
 				//				|| (XmlUtils.GetOptionalAttributeValue(caller, "expansion") == "expanded")
 				//				|| Expansion == DataTree.TreeItemState.ktisCollapsedEmpty)
-				bool fExpand = XmlUtils.GetOptionalAttributeValue(node, "expansion") == "expanded";
+				bool fExpand = XmlUtils.GetOptionalAttributeValue(node, "expansion") != "doNotExpand";
 				if (fUsePersistentExpansion && m_mediator != null) // mediator null only in testing?
 				{
 					Expansion = DataTree.TreeItemState.ktisCollapsed; // Needs to be an expandable state to have ExpansionStateKey.

Src/Generic/StackDumper.cpp

@@ -18,15 +18,6 @@ Modified: 24 Apr 2008 	- Non Win32 null implementation that attempted to preserv
 //:>	   Include files
 //:>********************************************************************************************
 #include "main.h"
-#include <windows.h>
-
-extern "C" USHORT WINAPI RtlCaptureStackBackTrace(
-  ULONG  FramesToSkip,
-  ULONG  FramesToCapture,
-  PVOID  *BackTrace,
-  PULONG BackTraceHash
-);
-
 #pragma hdrstop
 // any other headers (not precompiled)
 
@@ -120,20 +111,12 @@ int StackDumper::FindStartOfFrame(int ichStart)
 DWORD Filter( EXCEPTION_POINTERS *ep )
 {
 #if defined(_WIN32) || defined(_M_X64)
-	__try
-	{
-		HANDLE hThread;
+	HANDLE hThread;
 
-		DuplicateHandle( GetCurrentProcess(), GetCurrentThread(),
-			GetCurrentProcess(), &hThread, 0, false, DUPLICATE_SAME_ACCESS );
-		StackDumper::AppendShowStack( hThread, *(ep->ContextRecord) );
-		CloseHandle( hThread );
-	}
-	__except(EXCEPTION_EXECUTE_HANDLER)
-	{
-		// If something goes wrong generating the stack dump, just continue
-		// without it rather than crashing.
-	}
+	DuplicateHandle( GetCurrentProcess(), GetCurrentThread(),
+		GetCurrentProcess(), &hThread, 0, false, DUPLICATE_SAME_ACCESS );
+	StackDumper::AppendShowStack( hThread, *(ep->ContextRecord) );
+	CloseHandle( hThread );
 
 	return EXCEPTION_EXECUTE_HANDLER;
 #else
@@ -204,22 +187,30 @@ void TransFuncDump( unsigned int u, EXCEPTION_POINTERS * pExp)
 
 /*----------------------------------------------------------------------------------------------
 	Generate a dump of the stack at the point where this is called.
-	Uses CaptureStackBackTrace which is reliable on x64 and doesn't require dbghelp setup.
-	The addresses can be matched against MAP files post-mortem for symbolication.
 ----------------------------------------------------------------------------------------------*/
 void DumpStackHere(SDCHAR * pszMsg)
 {
-	// In containers/tests we avoid full stack capture; record a placeholder so
-	// error descriptions still include the developer-only marker and header the
-	// tests expect.
-	StackDumper::InitDump(pszMsg);
-
-	if (s_dumper.m_pstaDump)
+#if defined(_WIN32) || defined(_M_X64)
+		StackDumper::InitDump(pszMsg);
+	__try
 	{
-		const char * header = pszMsg ? pszMsg : "Stack Dump:\r\n";
-		s_dumper.m_pstaDump->Assign(header);
-		s_dumper.m_pstaDump->Append("Stack capture unavailable in this environment.\r\n");
+		//RaiseException(0, 0, 0, NULL); // Just to get FilterContiue called.
+		// Make a deliberate exception. For some reason, if we use RaiseException as above,
+		// the code crashes while returning from the exception handler. The exception won't
+		// be reported to the end user (since it is caught right here), but unfortunately
+		// it will show up in the debugger if you have it set to stop always.
+		// Enhance JohnT: maybe we could cause a less drastic exception that most people
+		// don't want to stop always?
+		char * pch = NULL;
+		*pch = 3;
 	}
+	__except ( Filter( GetExceptionInformation() ) )
+	{
+	}
+#else
+	CONTEXT unused;
+	StackDumper::ShowStack(NULL, unused, pszMsg);
+#endif
 }
 
 /*----------------------------------------------------------------------------------------------
@@ -518,17 +509,8 @@ HRESULT HandleThrowable(Throwable & thr, REFGUID iid, DummyFactory * pfact)
 			// Would it be better to strip off the path?
 			stuUserMsg.Format(stuUserMsgFmt, stuHrMsg.Chars(), stuModName.Chars());
 		}
-
-		if (stuUserMsg.Length())
-		{
-			stuDesc.Format(L"%s%S\r\n\r\n%s\r\n\r\n%s", ThrowableSd::MoreSep(), pchDump,
-				stuUserMsg.Chars(), GetModuleVersion(stuModName.Chars()).Chars());
-		}
-		else
-		{
-			stuDesc.Format(L"%s%S\r\n\r\n%s", ThrowableSd::MoreSep(), pchDump,
-				GetModuleVersion(stuModName.Chars()).Chars());
-		}
+		stuDesc.Format(L"%s%s%S\r\n\r\n%s", stuUserMsg.Chars(), ThrowableSd::MoreSep(), pchDump,
+			GetModuleVersion(stuModName.Chars()).Chars());
 	}
 	else
 	{

Src/Generic/StackDumperWin64.cpp

@@ -261,8 +261,8 @@ void StackDumper::ShowStackCoreInternal(HANDLE hThread, CONTEXT &c)
 			if (!g_pfnSymGetLineFromAddr64)
 			{
 				StrApp staModName("IMAGEHLP.DLL");
-				if (g_pfnSymGetLineFromAddr64 && gle != 487) // apparently a magic number indicating not in symbol file.
-					m_pstaDump->FormatAppend("SymGetLineFromAddr64(): gle = %u\r\n", gle);
+				g_pfnSymGetLineFromAddr64 = (PFNSYMGETLINEFROMADDR64PROC) GetProcAddress(
+					GetModuleHandle(staModName.Chars()), "SymGetLineFromAddr64");
 			}
 			DWORD lineDisplacement = 0;
 			if (!g_pfnSymGetLineFromAddr64 ||