ci: check public headers conform to c++ ISO standards #4166

Job	Run time
Build mlibc (x86_64, mlibc, gcc)	3m 46s
Compile sysdeps (dripos)	2m 25s
Build mlibc (x86_64, mlibc-static, gcc)	3m 0s
Compile sysdeps (lemon)	2m 19s
Build mlibc (x86_64, mlibc-shared, gcc)	3m 11s
Compile sysdeps (aero)	2m 46s
Build mlibc (x86_64, mlibc-ansi-only, gcc)	2m 53s
Compile sysdeps (ironclad)	2m 21s
Build mlibc (x86_64, mlibc-headers-only, gcc)	2m 28s
Compile sysdeps (lyre)	2m 31s
Build mlibc (riscv64, mlibc, gcc)	3m 43s
Compile sysdeps (keyronex)	2m 18s
Build mlibc (riscv64, mlibc-static, gcc)	4m 32s
Compile sysdeps (managarm)	2m 46s
Build mlibc (riscv64, mlibc-shared, gcc)	3m 27s
Compile sysdeps (vinix)	2m 22s
Build mlibc (riscv64, mlibc-ansi-only, gcc)	2m 52s
Compile sysdeps (astral)	2m 20s
Build mlibc (riscv64, mlibc-headers-only, gcc)	1m 56s
Build mlibc (aarch64, mlibc, gcc)	4m 9s
Build mlibc (aarch64, mlibc-static, gcc)	3m 23s
Build mlibc (aarch64, mlibc-shared, gcc)	3m 51s
Build mlibc (aarch64, mlibc-ansi-only, gcc)	4m 39s
Build mlibc (aarch64, mlibc-headers-only, gcc)	2m 10s
Build mlibc (x86, mlibc, gcc)	3m 53s
Build mlibc (x86, mlibc-static, gcc)	3m 20s
Build mlibc (x86, mlibc-shared, gcc)	3m 12s
Build mlibc (x86, mlibc-ansi-only, gcc)	3m 10s
Build mlibc (x86, mlibc-headers-only, gcc)	2m 6s
Build mlibc (m68k, mlibc, gcc)	3m 34s
Build mlibc (m68k, mlibc-static, gcc)	2m 53s
Build mlibc (m68k, mlibc-shared, gcc)	2m 55s
Build mlibc (m68k, mlibc-ansi-only, gcc)	2m 48s
Build mlibc (m68k, mlibc-headers-only, gcc)	2m 10s
Build mlibc (x86_64, mlibc, clang)	3m 9s
	1h 45m 18s

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