ntdll: Implement RtlWalkFrameChain on ARM64EC.

dlls/ntdll/signal_arm64ec.c

@@ -1995,6 +1995,38 @@ void WINAPI RtlUnwindEx( PVOID end_frame, PVOID target_ip, EXCEPTION_RECORD *rec
 }
 
 
+/*************************************************************************
+ *		RtlWalkFrameChain (NTDLL.@)
+ */
+ULONG WINAPI RtlWalkFrameChain( void **buffer, ULONG count, ULONG flags )
+{
+    UNWIND_HISTORY_TABLE table;
+    RUNTIME_FUNCTION *func;
+    PEXCEPTION_ROUTINE handler;
+    ULONG_PTR pc, frame, base;
+    CONTEXT context;
+    void *data;
+    ULONG i, skip = flags >> 8, num_entries = 0;
+
+    RtlCaptureContext( &context );
+
+    for (i = 0; i < count; i++)
+    {
+        pc = context.Rip;
+        if ((context.ContextFlags & CONTEXT_UNWOUND_TO_CALL) && RtlIsEcCode( pc )) pc -= 4;
+        func = RtlLookupFunctionEntry( pc, &base, &table );
+        if (RtlVirtualUnwind2( UNW_FLAG_NHANDLER, base, pc, func, &context, NULL,
+                               &data, &frame, NULL, NULL, NULL, &handler, 0 ))
+            break;
+        if (!context.Rip) break;
+        if (!frame || !is_valid_frame( frame )) break;
+        if (context.Rsp == (ULONG_PTR)NtCurrentTeb()->Tib.StackBase) break;
+        if (i >= skip) buffer[num_entries++] = (void *)context.Rip;
+    }
+    return num_entries;
+}
+
+
 /*******************************************************************
  *		__C_specific_handler (NTDLL.@)
  */