Update bashbrew-arch-to-goenv.sh with more edge cases

[tianon]

Also, Go updates (GOAMD64, GOARM64, etc)

$ for bashbrewArch in $(grep -oE '^[[:space:]]+"[^[:space:]]+":' architecture/oci-platform.go | cut -d'"' -f2); do echo "# $bashbrewArch"; ./scripts/bashbrew-arch-to-goenv.sh "$bashbrewArch"; echo; done
# amd64
export GOARCH=amd64 GOAMD64=v1 GOOS=linux
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOPPC64

# arm32v5
export GOARCH=arm GOARM=5 GOOS=linux
unset GO386 GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# arm32v6
export GOARCH=arm GOARM=6 GOOS=linux
unset GO386 GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# arm32v7
export GOARCH=arm GOARM=7 GOOS=linux
unset GO386 GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# arm64v8
export GOARCH=arm64 GOARM64=v8.0 GOOS=linux
unset GO386 GOARM GOMIPS64 GORISCV64 GOAMD64 GOPPC64

# i386
export GOARCH=386 GOOS=linux
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# mips64le
export GOARCH=mips64le GOOS=linux
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# ppc64le
export GOARCH=ppc64le GOOS=linux
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# riscv64
export GOARCH=riscv64 GOOS=linux
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# s390x
export GOARCH=s390x GOOS=linux
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOAMD64 GOPPC64

# windows-amd64
export GOARCH=amd64 GOAMD64=v1 GOOS=windows
unset GO386 GOARM GOMIPS64 GOARM64 GORISCV64 GOPPC64

[tianon]

Semi-related bits of code:

• https://github.com/docker-library/golang/blob/7db81882d183714657225ba6081ce0e9a0db9b75/versions.sh#L139-L157
• https://github.com/docker-library/meta-scripts/blob/5978683763b8d7844bf589e0dd4e76a31ef5cb1a/oci.jq#L9-L20

• bashbrew/architecture/oci-platform.go

  Lines 14 to 27 in f71d6ef

  	var SupportedArches = map[string]OCIPlatform{
  	"amd64": {OS: "linux", Architecture: "amd64"},
  	"arm32v5": {OS: "linux", Architecture: "arm", Variant: "v5"},
  	"arm32v6": {OS: "linux", Architecture: "arm", Variant: "v6"},
  	"arm32v7": {OS: "linux", Architecture: "arm", Variant: "v7"},
  	"arm64v8": {OS: "linux", Architecture: "arm64", Variant: "v8"},
  	"i386": {OS: "linux", Architecture: "386"},
  	"mips64le": {OS: "linux", Architecture: "mips64le"},
  	"ppc64le": {OS: "linux", Architecture: "ppc64le"},
  	"riscv64": {OS: "linux", Architecture: "riscv64"},
  	"s390x": {OS: "linux", Architecture: "s390x"},
  	"windows-amd64": {OS: "windows", Architecture: "amd64"},
  	}