Fix 'index' var shadowing with old toolchains (#2540)
Fix 'index' var shadowing with old toolchains (#2540)


PKRoma/s2n,awslabs/s2n,wcs1only/s2n,PKRoma/s2n,wcs1only/s2n,awslabs/s2n,PKRoma/s2n,PKRoma/s2n,wcs1only/s2n,awslabs/s2n,awslabs/s2n,awslabs/s2n,wcs1only/s2n,PKRoma/s2n,wcs1only/s2n,wcs1only/s2n,PKRoma/s2n,wcs1only/s2n,awslabs/s2n,wcs1only/s2n,PKRoma/s2n,PKRoma/s2n