Fix x86 runtime async frame pointer mismatch in GetSpForDiagnosticReporting (#126717)

For certain runtime async frames this resulted in the
`ICorDebugManagedCallback2::Exception` to return a null `ICorDebugFrame`
for `DEBUG_EXCEPTION_CATCH_HANDLER_FOUND` notifications. The fix
addresses this by adjusting `GetSpForDiagnosticReporting` to account for
runtime async variant method stack layout differences on x86.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: tommcdon

src/coreclr/debug/di/rsthread.cpp

@@ -1412,13 +1412,13 @@ HRESULT CordbThread::FindFrame(ICorDebugFrame ** ppFrame, FramePointer fp)
         ICorDebugFrame * pIFrame = pSSW->GetFrame(i);
         CordbFrame * pCFrame = CordbFrame::GetCordbFrameFromInterface(pIFrame);
 
-#if defined(HOST_64BIT)
-        // On 64-bit we can simply compare the FramePointer.
+#if !defined(TARGET_X86)
+        // Compare the FramePointer to determine if the frame matches
         if (pCFrame->GetFramePointer() == fp)
-#else  // !HOST_64BIT
-        // On other platforms, we need to do a more elaborate check.
+#else
+        // On x86 we need to do a more elaborate check.  The reason is that on x86, the FramePointer is always the same as the value of EBP, so we can just check if the input FramePointer is contained in the frame.  However, on other platforms, the FramePointer may not be the same as the value of RSP, so we need to check if the input FramePointer is the same as the one of the frame.
         if (pCFrame->IsContainedInFrame(fp))
-#endif // HOST_64BIT
+#endif
         {
             *ppFrame = pIFrame;
             (*ppFrame)->AddRef();
@@ -4773,6 +4773,27 @@ bool CordbFrame::IsContainedInFrame(FramePointer fp)
 
     CORDB_ADDRESS sp  = PTR_TO_CORDB_ADDRESS(fp.GetSPValue());
 
+#if defined(TARGET_X86)
+    // On x86, the runtime sends CallerSP - sizeof(TADDR) as the frame pointer
+    // for exception notifications (see GetSpForDiagnosticReporting). Since this
+    // does not account for the stack parameter size, we adjust for it here.
+    if (sp > stackEnd)
+    {
+        CordbNativeFrame * pNativeFrame = GetAsNativeFrame();
+        if (pNativeFrame != NULL)
+        {
+            CORDB_ADDRESS codeAddr = pNativeFrame->GetNativeCode()->GetAddress();
+            ULONG32 stackParamSize = 0;
+            IDacDbiInterface * pDAC = GetProcess()->GetDAC();
+            if (SUCCEEDED(pDAC->GetStackParameterSize(codeAddr + m_ip, &stackParamSize))
+                && stackParamSize > 0)
+            {
+                sp -= stackParamSize;
+            }
+        }
+    }
+#endif // TARGET_X86
+
     if ((stackStart <= sp) && (sp <= stackEnd))
     {
         return true;