ld: dockerfile enhancements #255

Job	Run time
ld-targets	6s
ld64	50m 41s
binutils-targets	3s
utils-lipo	1m 26s
utils-sigtool	1m 59s
binutils (binutils-linux-386-alpine)	18m 22s
binutils (binutils-linux-amd64-alpine)	19m 15s
binutils (binutils-linux-arm64-alpine)	18m 30s
binutils (binutils-linux-armv6-alpine)	17m 56s
binutils (binutils-linux-armv7-alpine)	17m 59s
binutils (binutils-linux-ppc64le-alpine)	19m 11s
binutils (binutils-linux-riscv64-alpine)	10m 43s
binutils (binutils-linux-s390x-alpine)	17m 57s
binutils (binutils-windows-386-alpine)	10m 37s
binutils (binutils-windows-amd64-alpine)	10m 40s
ld (ld-linux-386-static-tgz)	16m 16s
ld (ld-linux-amd64-static-tgz)	16m 12s
ld (ld-linux-arm64-static-tgz)	16m 32s
ld (ld-linux-armv6-static-tgz)	15m 49s
ld (ld-linux-armv7-static-tgz)	15m 36s
ld (ld-linux-ppc64le-static-tgz)	17m 3s
ld (ld-linux-riscv64-static-tgz)	16m 59s
ld (ld-linux-s390x-static-tgz)	15m 49s
ld (ld-windows-386-static-tgz)	16m 32s
ld (ld-windows-amd64-static-tgz)	16m 50s
release	0s
	6h 19m 3s

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