[libc++] Refactor the sequence container benchmarks #8775

Job	Run time
stage1 (frozen-cxx03-headers, clang-19, clang++-19)	7m 40s
stage1 (generic-cxx03, clang-19, clang++-19)	8m 3s
stage1 (generic-cxx26, clang-19, clang++-19)	13m 33s
stage1 (generic-modules, clang-19, clang++-19)	10m 28s
stage1 (generic-gcc, gcc-14, g++-14)	20m 54s
macos (generic-cxx03, macos-15)	13m 6s
windows (clang-cl-dll, false)	49m 49s
macos (generic-cxx23, macos-15)	35m 48s
stage2 (generic-cxx11, clang-19, clang++-19)	8m 4s
windows (clang-cl-static, false)	57m 35s
macos (generic-modules, macos-15)	20m 33s
stage2 (generic-cxx14, clang-19, clang++-19)	8m 30s
windows (clang-cl-no-vcruntime, false)	50m 55s
macos (apple-configuration, macos-15)	27m 49s
stage2 (generic-cxx17, clang-19, clang++-19)	10m 10s
windows (clang-cl-debug, false)	51m 12s
macos (apple-system, macos-13)	51m 38s
stage2 (generic-cxx20, clang-19, clang++-19)	17m 15s
windows (clang-cl-static-crt, false)	54m 10s
macos (apple-system-hardened, macos-13)	1h 3m 26s
stage2 (generic-cxx23, clang-19, clang++-19)	13m 34s
windows (mingw-dll, true)	1h 12m 42s
stage2 (generic-gcc-cxx11, gcc-14, g++-14)	8m 26s
windows (mingw-static, true)	1h 10m 32s
stage2 (generic-cxx23, clang-17, clang++-17)	15m 28s
windows (mingw-dll-i686, true)	1h 10m 1s
stage2 (generic-cxx26, clang-18, clang++-18)	14m 29s
windows (mingw-incomplete-sysroot, true)	6m 51s
stage3	0s
	14h 12m 41s

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