Add some key macros for Shift+x and Control+x keys

For use by SyncTERM in Mode 7/Prestel modes.

src/conio/ciolib.h

@@ -763,6 +763,16 @@ CIOLIBEXPORT void mousestate_res(int *x_res, int *y_res, uint8_t *buttons);
 #define CIO_KEY_CTRL_F(x)   ((x<11)?((0x5d + x) << 8):((0x7e + x) << 8))
 #define CIO_KEY_ALT_F(x)    ((x<11)?((0x67 + x) << 8):((0x80 + x) << 8))
 #define CIO_KEY_BACKTAB     (0x0f << 8)
+#define CIO_KEY_SHIFT_UP    (0x38 << 8)
+#define CIO_KEY_CTRL_UP     (0x8d << 8)
+#define CIO_KEY_SHIFT_LEFT  (0x34 << 8)
+#define CIO_KEY_CTRL_LEFT   (0x73 << 8)
+#define CIO_KEY_SHIFT_RIGHT (0x36 << 8)
+#define CIO_KEY_CTRL_RIGHT  (0x74 << 8)
+#define CIO_KEY_SHIFT_DOWN  (0x32 << 8)
+#define CIO_KEY_CTRL_DOWN   (0x91 << 8)
+#define CIO_KEY_SHIFT_END   (0x31 << 8)
+#define CIO_KEY_CTRL_END    (0x75 << 8)
 
 #define CIO_KEY_MOUSE     0x7dE0	// This is the right mouse on Schneider/Amstrad PC1512 PC keyboards "F-14"
 #define CIO_KEY_QUIT	  0x7eE0	// "F-15"