[stdlib] add countof()
[stdlib] add countof()

pichina/lk,beidl/lk_umia,DooMLoRD/android_bootable_bootloader_lk,oubeichen/lk-v500,M1cha/lktris,zhuotong/mi2_lk_NoEmmc,zhuotong/mi2_lk_NoEmmc,idor/dk50-bootable_bootloader_lk,t2m-foxfone/android_kernel_lk,idor/dk50-bootable_bootloader_lk,oubeichen/lk-v500,t2m-foxfone/kernel_lk,my4ndr0id/android_bootable_bootloader_lk,mozilla-b2g/kernel_lk,jcsullins/moboot,M1cha/android_bootable_bootloader_lk,zhuotong/mi2_lk_NoEmmc,utilite2/lk,jsr-d9/android_kernel_lk,jbott/lk_gee,mozilla-b2g/kernel_lk,lg-devs/g2-bootloader,chirayudesai/android_bootable_bootloader_lk,M1cha/mi2_lk,jbott/lk_gee,t2m-foxfone/android_kernel_lk,Blefish/android_bootable_bootloader_lk,xndcn/moboot-for-veer,Foxda-Tech/argo8-bootable-bootloader-lk,Foxda-Tech/argo8-bootable-bootloader-lk,Blefish/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk,MiCode/mi2_lk,efidroid/lk,xndcn/moboot-for-veer,detule/lk-g2-spr,Redmi-dev/android_bootable_lk,Blefish/android_bootable_bootloader_lk,xndcn/moboot-for-veer,Blefish/android_bootable_bootloader_lk,pichina/lk,xndcn/moboot-for-veer,lg-devs/g2-bootloader,efidroid/lk,mozilla-b2g/fairphone2_kernel_lk,CanarySolutions/little-kernel,t2m-foxfone/kernel_lk,jsr-d9/android_kernel_lk,DooMLoRD/android_bootable_bootloader_lk,chirayudesai/android_bootable_bootloader_lk,Foxda-Tech/argo8-bootable-bootloader-lk,RonGokhale/android_lk_bootloader,jsr-d10/android_bootable_bootloader_lk,oubeichen/lk-v500,my4ndr0id/android_bootable_bootloader_lk,jsr-d9/android_kernel_lk,Redmi-dev/android_bootable_lk,utilite2/lk,MiCode/mi2_lk,jsr-d9/android_kernel_lk,detule/lk-g2-spr,utilite2/lk,beidl/lk_umia,idor/dk50-bootable_bootloader_lk,hanjae/lumiab0,efidroid/lk,hanjae/lumiab0,CanarySolutions/little-kernel,Redmi-dev/android_bootable_lk,mozilla-b2g/fairphone2_kernel_lk,hanjae/lumiab0,CanarySolutions/little-kernel,jsr-d10/android_bootable_bootloader_lk,chirayudesai/android_bootable_bootloader_lk,thornbirdblue/codeaurora_lk,t2m-foxfone/kernel_lk,idor/dk50-bootable_bootloader_lk,oubeichen/lk-v500,t2m-foxfone/kernel_lk,hanjae/lumiab0,M1cha/mi2_lk,MiCode/mi2_lk,M1cha/mi2_lk,mozilla-b2g/fairphone2_kernel_lk,Foxda-Tech/polaris-bootable-bootloader-lk,Redmi-dev/android_bootable_lk,pichina/lk,lg-devs/g2-bootloader,jcsullins/moboot,detule/lk-g2-spr,CanarySolutions/little-kernel,Foxda-Tech/polaris-bootable-bootloader-lk,zhuotong/mi2_lk_NoEmmc,my4ndr0id/android_bootable_bootloader_lk,M1cha/mi2_lk,M1cha/android_bootable_bootloader_lk,jbott/lk_gee,lg-devs/g2-bootloader,efidroid/lk,idor/dk50-bootable_bootloader_lk,Foxda-Tech/argo8-bootable-bootloader-lk,M1cha/android_bootable_bootloader_lk,mozilla-b2g/fairphone2_kernel_lk,M1cha/android_bootable_bootloader_lk,chirayudesai/android_bootable_bootloader_lk,Redmi-dev/android_bootable_lk,MiCode/mi2_lk,my4ndr0id/android_bootable_bootloader_lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,my4ndr0id/android_bootable_bootloader_lk,thornbirdblue/codeaurora_lk,M1cha/lktris,mozilla-b2g/kernel_lk,beidl/lk_umia,t2m-foxfone/android_kernel_lk,t2m-foxfone/android_kernel_lk,pichina/lk,detule/lk-g2-spr,oubeichen/lk-v500,thornbirdblue/codeaurora_lk,mozilla-b2g/kernel_lk,DooMLoRD/android_bootable_bootloader_lk,DooMLoRD/android_bootable_bootloader_lk,RonGokhale/android_lk_bootloader,M1cha/lktris,jbott/lk_gee,xndcn/moboot-for-veer,hanjae/lumiab0,jsr-d10/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk,chirayudesai/android_bootable_bootloader_lk,DooMLoRD/android_bootable_bootloader_lk,thornbirdblue/codeaurora_lk,RonGokhale/android_lk_bootloader,M1cha/android_bootable_bootloader_lk,zhuotong/mi2_lk_NoEmmc,M1cha/lktris,M1cha/lktris,lg-devs/g2-bootloader,beidl/lk_umia,thornbirdblue/codeaurora_lk,RonGokhale/android_lk_bootloader,jbott/lk_gee,jcsullins/moboot,jcsullins/moboot,MiCode/mi2_lk,Foxda-Tech/argo8-bootable-bootloader-lk,M1cha/mi2_lk,jcsullins/moboot,t2m-foxfone/android_kernel_lk,Foxda-Tech/polaris-bootable-bootloader-lk,efidroid/lk,jcsullins/moboot,utilite2/lk,detule/lk-g2-spr,RonGokhale/android_lk_bootloader,Blefish/android_bootable_bootloader_lk,utilite2/lk,pichina/lk,M1cha/android_bootable_bootloader_lk,mozilla-b2g/kernel_lk,beidl/lk_umia,t2m-foxfone/kernel_lk,mozilla-b2g/fairphone2_kernel_lk,CanarySolutions/little-kernel,jsr-d9/android_kernel_lk