patch 9.1.0660: MS-Windows: Shift-Insert does work on old conhost

Problem:  MS-Windows: Shift-Insert does not work on old conhost
          (Nick Jensen, after 9.0.1146)
Solution: handle Shift-Insert specifically
          (Christian Plewright)

fixes: #15326
closes: #15430

Signed-off-by: Christopher Plewright <chris@createng.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/os_win32.c b/src/os_win32.c
index eeb3b47..44d92c0 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -1264,6 +1264,13 @@
 				}
 			    }
 			}
+			else if (pker->wVirtualKeyCode == VK_INSERT
+					&& (nModifs & SHIFT) != 0
+					&& (nModifs & ~SHIFT) == 0)
+			{
+			    *pmodifiers = 0;
+			    *pch2 = VirtKeyMap[i].chShift;
+			}
 			else
 			{
 			    *pch2 = VirtKeyMap[i].chAlone;