tcg: Remove unused TCG_CALL_DUMMY_TCGV

Reviewed-by: NEmilio G. Cota <cota@braap.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NRichard Henderson <rth@twiddle.net>

tcg/tcg.h

@@ -496,7 +496,6 @@ static inline intptr_t QEMU_ARTIFICIAL GET_TCGV_PTR(TCGv_ptr t)
 #define TCG_CALL_NO_WG_SE       (TCG_CALL_NO_WG | TCG_CALL_NO_SE)
 
 /* used to align parameters */
-#define TCG_CALL_DUMMY_TCGV     MAKE_TCGV_I32(-1)
 #define TCG_CALL_DUMMY_ARG      ((TCGArg)(-1))
 
 /* Conditions.  Note that these are laid out for easy manipulation by