oss-fuzz: add test case for integer overflow in inv_adst16_1d

../../src/dav1d/src/itx_1d.c:803:40: runtime error: signed integer overflow: -924106 * 2896 cannot be represented in type 'int'
     #0 0x4b9192 in inv_adst16_1d /src/dav1d/src/itx_1d.c:803:40
     #1 0x4b3e5d in inv_txfm_add_c /src/dav1d/src/itx_tmpl.c:0
     #2 0x4b289f in inv_txfm_add_adst_identity_16x4_c /src/dav1d/src/itx_tmpl.c:140:1
    #3 0x4d6b47 in read_coef_tree /src/dav1d/src/recon_tmpl.c:353:17
    #4 0x4dd7b4 in dav1d_recon_b_inter_16bpc /src/dav1d/src/recon_tmpl.c:1505:21
    #5 0x44ccc7 in decode_b /src/dav1d/src/decode.c:1827:17
    #6 0x43d2e9 in decode_sb /src/dav1d/src/decode.c:2072:17
    #7 0x43dbd3 in decode_sb /src/dav1d/src/decode.c:2005:21
    #8 0x43cd41 in decode_sb /src/dav1d/src/decode.c:2155:17
    #9 0x43c041 in dav1d_decode_tile_sbrow /src/dav1d/src/decode.c:2469:13