[make] remove -fno-builtin
[make] remove -fno-builtin

fno-builtin was mostly unnecessary before, but required some libc
work to run without it, due to standard function signature mismatches.

pablomarx/lk,skabet/lk,skabet/lk,GCrean/lk,ErikCorryGoogle/lk,travisg/lk,hollanderic/lkstuff,sndnvaps/lk,sndnvaps/lk,ErikCorryGoogle/lk,srodrig1/lk,minglun-tsai/lk,M1cha/lk,skabet/lk,ErikCorryGoogle/lk,pablomarx/lk,travisg/lk,srodrig1/lk,hollanderic/lkstuff,srodrig1/lk,nvll/lk,grub4android/lk,littlekernel/lk,littlekernel/lk,srodrig1/lk,nvll/lk,hollanderic/lkstuff,littlekernel/lk,GCrean/lk,skabet/lk,minglun-tsai/lk,nvll/lk,pablomarx/lk,minglun-tsai/lk,M1cha/lk,M1cha/lk,littlekernel/lk,nvll/lk,sndnvaps/lk,hollanderic/lkstuff,M1cha/lk,sndnvaps/lk,grub4android/lk,pablomarx/lk,GCrean/lk,skabet/lk,travisg/lk,minglun-tsai/lk,grub4android/lk,M1cha/lk,grub4android/lk,sndnvaps/lk,pablomarx/lk,grub4android/lk,srodrig1/lk,GCrean/lk,GCrean/lk,travisg/lk,nvll/lk,ErikCorryGoogle/lk