Crash Seen with unspecified micro arch for Windows On Arm devices when getting the cpu micro arch info to check the core type

[yganup]

For WOA(windows on ARM) devices where the CPU string does not match any string in woa_chips, cpuinfo_get_uarch returns NULL (index = 0 and cpuinfo_uarchs_count = 0 for unspecified CPU).

const struct cpuinfo_uarch_info* cpuinfo_get_uarch(uint32_t index) {
    if (!cpuinfo_is_initialized) {
        cpuinfo_log_fatal("cpuinfo_get_%s called before cpuinfo is initialized", "uarch");
    }
#if CPUINFO_ARCH_ARM || CPUINFO_ARCH_ARM64 || CPUINFO_ARCH_RISCV32 || CPUINFO_ARCH_RISCV64
    if CPUINFO_UNLIKELY (index >= cpuinfo_uarchs_count) {
         return NULL; 
    }
    return &cpuinfo_uarchs[index];
#else
    if CPUINFO_UNLIKELY (index != 0) {
        return NULL;
    }
    return &cpuinfo_global_uarch;
#endif

To gracefully handle return of cpuinfo_uarch_info below are the 2 methods can be used

1. Return a dummy cpuinfo_uarch_info struct with uarch = cpuinfo_uarch_unknown (0) instead of NULL.
2. As part of usage guidelines for _cpuinfo_getuarch, Include NULL checking for return value

// check for ARM cortex a-53 CPU 
cpuinfo_uarch_info *cpu_data = cpuinfo_get_uarch(cpuinfo_get_current_uarch_index())

if( cpu_data!= NULL)
{
 switch (cpu_data->uarch){
   case cpuinfo_uarch_cortex_a53:
   case cpuinfo_uarch_cortex_a55r0:
   case cpuinfo_uarch_cortex_a55:
     return true;
   default:
     return false;
 }
return false

This would help stability of libraries/binaries using cpuinfo on devices with unknown micro arch for Windows on ARM devices . Also I would assume the same issue would be seen for other platforms as well.