AMDGPU/SI: Remove non-existent flat instructions

[arsenm]

LGTM

llvm/trunk/lib/Target/AMDGPU/CIInstructions.td

def FLAT_STORE_DWORDX3 : FLAT_Store_Helper <
   0x1f, "flat_store_dwordx3", VReg_96
 >;
 defm FLAT_ATOMIC_SWAP : FLAT_ATOMIC <0x30, "flat_atomic_swap", VGPR_32>;
 defm FLAT_ATOMIC_CMPSWAP : FLAT_ATOMIC <
   0x31, "flat_atomic_cmpswap", VGPR_32, VReg_64
 >;
 defm FLAT_ATOMIC_ADD : FLAT_ATOMIC <0x32, "flat_atomic_add", VGPR_32>;
 defm FLAT_ATOMIC_SUB : FLAT_ATOMIC <0x33, "flat_atomic_sub", VGPR_32>;
-defm FLAT_ATOMIC_RSUB : FLAT_ATOMIC <0x34, "flat_atomic_rsub", VGPR_32>;
 defm FLAT_ATOMIC_SMIN : FLAT_ATOMIC <0x35, "flat_atomic_smin", VGPR_32>;
 defm FLAT_ATOMIC_UMIN : FLAT_ATOMIC <0x36, "flat_atomic_umin", VGPR_32>;
 defm FLAT_ATOMIC_SMAX : FLAT_ATOMIC <0x37, "flat_atomic_smax", VGPR_32>;
 defm FLAT_ATOMIC_UMAX : FLAT_ATOMIC <0x38, "flat_atomic_umax", VGPR_32>;
 defm FLAT_ATOMIC_AND : FLAT_ATOMIC <0x39, "flat_atomic_and", VGPR_32>;
 defm FLAT_ATOMIC_OR : FLAT_ATOMIC <0x3a, "flat_atomic_or", VGPR_32>;
 defm FLAT_ATOMIC_XOR : FLAT_ATOMIC <0x3b, "flat_atomic_xor", VGPR_32>;
 defm FLAT_ATOMIC_INC : FLAT_ATOMIC <0x3c, "flat_atomic_inc", VGPR_32>;
 defm FLAT_ATOMIC_DEC : FLAT_ATOMIC <0x3d, "flat_atomic_dec", VGPR_32>;
 defm FLAT_ATOMIC_FCMPSWAP : FLAT_ATOMIC <
   0x3e, "flat_atomic_fcmpswap", VGPR_32, VReg_64
 >;
 defm FLAT_ATOMIC_FMIN : FLAT_ATOMIC <0x3f, "flat_atomic_fmin", VGPR_32>;
 defm FLAT_ATOMIC_FMAX : FLAT_ATOMIC <0x40, "flat_atomic_fmax", VGPR_32>;
 defm FLAT_ATOMIC_SWAP_X2 : FLAT_ATOMIC <0x50, "flat_atomic_swap_x2", VReg_64>;
 defm FLAT_ATOMIC_CMPSWAP_X2 : FLAT_ATOMIC <
   0x51, "flat_atomic_cmpswap_x2", VReg_64, VReg_128
 >;
 defm FLAT_ATOMIC_ADD_X2 : FLAT_ATOMIC <0x52, "flat_atomic_add_x2", VReg_64>;
 defm FLAT_ATOMIC_SUB_X2 : FLAT_ATOMIC <0x53, "flat_atomic_sub_x2", VReg_64>;
-defm FLAT_ATOMIC_RSUB_X2 : FLAT_ATOMIC <0x54, "flat_atomic_rsub_x2", VReg_64>;
 defm FLAT_ATOMIC_SMIN_X2 : FLAT_ATOMIC <0x55, "flat_atomic_smin_x2", VReg_64>;
 defm FLAT_ATOMIC_UMIN_X2 : FLAT_ATOMIC <0x56, "flat_atomic_umin_x2", VReg_64>;
 defm FLAT_ATOMIC_SMAX_X2 : FLAT_ATOMIC <0x57, "flat_atomic_smax_x2", VReg_64>;
 defm FLAT_ATOMIC_UMAX_X2 : FLAT_ATOMIC <0x58, "flat_atomic_umax_x2", VReg_64>;
 defm FLAT_ATOMIC_AND_X2 : FLAT_ATOMIC <0x59, "flat_atomic_and_x2", VReg_64>;
 defm FLAT_ATOMIC_OR_X2 : FLAT_ATOMIC <0x5a, "flat_atomic_or_x2", VReg_64>;
 defm FLAT_ATOMIC_XOR_X2 : FLAT_ATOMIC <0x5b, "flat_atomic_xor_x2", VReg_64>;
 defm FLAT_ATOMIC_INC_X2 : FLAT_ATOMIC <0x5c, "flat_atomic_inc_x2", VReg_64>;