LRU/reclamation work #1056

Job	Run time
build-minimal-sysroots (x86_64)	1m 10s
build-minimal-sysroots (riscv64)	1m 18s
build-minimal-sysroots (arm64)	56s
build-toolchains (ubuntu-latest, x86_64, gnu)	36s
build-toolchains (ubuntu-latest, riscv64, gnu)	35s
build-toolchains (ubuntu-latest, arm64, gnu)	28s
build-toolchains (ubuntu-20.04, x86_64, gnu)	34s
build-toolchains (ubuntu-20.04, riscv64, gnu)	46s
build-toolchains (ubuntu-20.04, arm64, gnu)	28s
build-toolchains (macos-latest, x86_64, gnu)	1m 9s
build-toolchains (macos-latest, riscv64, gnu)	1m 7s
build-toolchains (macos-latest, arm64, gnu)	52s
build-toolchains (ubuntu-latest, llvm, all)	1h 46m 8s
build-arm64	3m 19s
build-llvm	2m 58s
build-llvm-arm64	2m 43s
build	3m 30s
build-llvm-riscv64	2m 40s
build-riscv	2m 36s
run-riscv	0s
run-riscv64-llvm	0s
run-x86_64	0s
run-x86_64-llvm	0s
	2h 13m 53s

Provide feedback