Implement _SC_{AV}PHYS_PAGES sysconfs #4214

Job	Run time
Compile sysdeps (dripos)	2m 24s
Compile sysdeps (lemon)	2m 26s
Compile sysdeps (aero)	2m 26s
Compile sysdeps (ironclad)	2m 24s
Compile sysdeps (lyre)	2m 48s
Build mlibc (x86_64, mlibc, gcc)	3m 47s
Compile sysdeps (keyronex)	2m 42s
Compile sysdeps (managarm)	3m 8s
Build mlibc (x86_64, mlibc-static, gcc)	3m 12s
Build mlibc (x86_64, mlibc-shared, gcc)	3m 4s
Compile sysdeps (vinix)	2m 27s
Build mlibc (x86_64, mlibc-ansi-only, gcc)	2m 56s
Compile sysdeps (astral)	2m 21s
Build mlibc (x86_64, mlibc-headers-only, gcc)	1m 59s
Build mlibc (riscv64, mlibc, gcc)	3m 49s
Build mlibc (riscv64, mlibc-static, gcc)	4m 37s
Build mlibc (riscv64, mlibc-shared, gcc)	3m 4s
Build mlibc (riscv64, mlibc-ansi-only, gcc)	2m 56s
Build mlibc (riscv64, mlibc-headers-only, gcc)	1m 58s
Build mlibc (aarch64, mlibc, gcc)	4m 27s
Build mlibc (aarch64, mlibc-static, gcc)	3m 25s
Build mlibc (aarch64, mlibc-shared, gcc)	3m 42s
Build mlibc (aarch64, mlibc-ansi-only, gcc)	3m 14s
Build mlibc (aarch64, mlibc-headers-only, gcc)	2m 8s
Build mlibc (x86, mlibc, gcc)	3m 56s
Build mlibc (x86, mlibc-static, gcc)	3m 14s
Build mlibc (x86, mlibc-shared, gcc)	3m 7s
Build mlibc (x86, mlibc-ansi-only, gcc)	3m 36s
Build mlibc (x86, mlibc-headers-only, gcc)	2m 28s
Build mlibc (m68k, mlibc, gcc)	3m 39s
Build mlibc (m68k, mlibc-static, gcc)	3m 2s
Build mlibc (m68k, mlibc-shared, gcc)	3m 10s
Build mlibc (m68k, mlibc-ansi-only, gcc)	2m 54s
Build mlibc (m68k, mlibc-headers-only, gcc)	2m 2s
Build mlibc (x86_64, mlibc, clang)	3m 14s
	1h 45m 46s

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