ld: dockerfile enhancements #268

Job	Run time
utils-lipo	1m 38s
ld64	28m 15s
ld-targets	4s
binutils-targets	7s
utils-sigtool	2m 0s
binutils (binutils-linux-386-alpine)	18m 44s
binutils (binutils-linux-amd64-alpine)	18m 59s
binutils (binutils-linux-arm64-alpine)	18m 59s
binutils (binutils-linux-armv6-alpine)	18m 0s
binutils (binutils-linux-armv7-alpine)	18m 29s
binutils (binutils-linux-ppc64le-alpine)	17m 52s
binutils (binutils-linux-riscv64-alpine)	11m 7s
binutils (binutils-linux-s390x-alpine)	18m 7s
binutils (binutils-windows-386-alpine)	11m 2s
binutils (binutils-windows-amd64-alpine)	11m 16s
ld (ld-linux-386-static-tgz)	16m 9s
ld (ld-linux-amd64-static-tgz)	15m 53s
ld (ld-linux-arm64-static-tgz)	17m 19s
ld (ld-linux-armv6-static-tgz)	15m 58s
ld (ld-linux-armv7-static-tgz)	16m 13s
ld (ld-linux-ppc64le-static-tgz)	16m 52s
ld (ld-linux-riscv64-static-tgz)	16m 46s
ld (ld-linux-s390x-static-tgz)	16m 9s
ld (ld-windows-386-static-tgz)	14m 16s
ld (ld-windows-amd64-static-tgz)	14m 10s
release	1s
	5h 54m 25s

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