Integer Overflow and affect top level software

[bibisec]

X265/source/common/x86/pixel-a.asm L13742

here:mmsize=0x20 R5 = (R2&0xffffffe0) – 0x20 when R2<0x20 : there is an Interger overflow for R5

I find this bug when I test libbpg. The poc is for libbpg, but the bug is belong to x265lib.In the poc R2=0x10