x/mobile: Replace hardcoded -miphoneos-version-min with command line arg

[tadovas]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.9.2 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/tadovas/work/go/openvpnv3-go-bindings"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.9.2/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.9.2/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/_j/73ymsvw56v989xyfwn6q18_m0000gn/T/go-build474754005=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

Trying to gomobile bind package with precompiled object files with newer iOS version (10.3

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

Successful bind

What did you see instead?

Warnings like "ld: warning: object file ... was built for newer iOS version (10.3) than being linked (7.0)"
And bind fails with linking errors, because iOS 10.x uses newer std c++ lib abi

This is more like proposal or feature: to remove hardcoded -miphoneos-version-min flags passed to clang and parameterize them instread (the same goes with ios simulator)

A new parameter could look like that gomobile bind -iosversion=10.3 (-iossimversion=10.3 respectively)

[tadovas]

PR implementing this: golang/mobile#21

[dmitshur]

Fixed by CL 135415, closing.

(It didn't get the "Fixes" format quite right, hence didn't get closed automatically.)