cmd/gomobile: add CGO_ENABLED=1 to gobind runs

A previous CL switched gobind to use the "source" importer so go
files using cgo can be type checked. However, CGO_ENABLED=1 also
have to be passed in for such files not be ignored.

Also add -tags ios to the gomobile test output missing from CL
99777.

Fixes golang/go#24941

Change-Id: I868469af3061b82ab592899e365a8a90a0333e58
Reviewed-on: https://go-review.googlesource.com/108336
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/bind/testdata/cgopkg/cgopkg.go b/bind/testdata/cgopkg/cgopkg.go
new file mode 100644
index 0000000..567bba4
--- /dev/null
+++ b/bind/testdata/cgopkg/cgopkg.go
@@ -0,0 +1,7 @@
+package cgopkg
+
+import (
+	_ "golang.org/x/mobile/gl"
+)
+
+func Dummy() {}
diff --git a/cmd/gobind/gobind_test.go b/cmd/gobind/gobind_test.go
index a856da8..ed3f598 100644
--- a/cmd/gobind/gobind_test.go
+++ b/cmd/gobind/gobind_test.go
@@ -22,6 +22,7 @@
 	{"Go-Testpkg", "go", "golang.org/x/mobile/bind/testdata/testpkg", ""},
 	{"Java-Javapkg", "java", "golang.org/x/mobile/bind/testdata/testpkg/javapkg", "android"},
 	{"Go-Javapkg", "go", "golang.org/x/mobile/bind/testdata/testpkg/javapkg", "android"},
+	{"Go-Javapkg", "go,java,objc", "golang.org/x/mobile/bind/testdata/cgopkg", "android"},
 }
 
 func installGobind() error {
@@ -35,6 +36,7 @@
 	cmd := exec.Command("gobind", "-lang", lang, pkg)
 	if goos != "" {
 		cmd.Env = append(os.Environ(), "GOOS="+goos)
+		cmd.Env = append(os.Environ(), "CGO_ENABLED=1")
 	}
 	if out, err := cmd.CombinedOutput(); err != nil {
 		return fmt.Errorf("gobind -lang %s %s failed: %v: %s", lang, pkg, err, out)
diff --git a/cmd/gomobile/bind_androidapp.go b/cmd/gomobile/bind_androidapp.go
index 2f65333..9897fbd 100644
--- a/cmd/gomobile/bind_androidapp.go
+++ b/cmd/gomobile/bind_androidapp.go
@@ -34,6 +34,7 @@
 		"-outdir="+tmpdir,
 	)
 	cmd.Env = append(cmd.Env, "GOOS=android")
+	cmd.Env = append(cmd.Env, "CGO_ENABLED=1")
 	if len(ctx.BuildTags) > 0 {
 		cmd.Args = append(cmd.Args, "-tags="+strings.Join(ctx.BuildTags, ","))
 	}
diff --git a/cmd/gomobile/bind_iosapp.go b/cmd/gomobile/bind_iosapp.go
index 97fc670..7b7fe69 100644
--- a/cmd/gomobile/bind_iosapp.go
+++ b/cmd/gomobile/bind_iosapp.go
@@ -22,6 +22,7 @@
 		"-outdir="+tmpdir,
 	)
 	cmd.Env = append(cmd.Env, "GOOS=darwin")
+	cmd.Env = append(cmd.Env, "CGO_ENABLED=1")
 	if len(ctx.BuildTags) > 0 {
 		cmd.Args = append(cmd.Args, "-tags="+strings.Join(ctx.BuildTags, ","))
 	}
diff --git a/cmd/gomobile/bind_test.go b/cmd/gomobile/bind_test.go
index 62adf38..5129590 100644
--- a/cmd/gomobile/bind_test.go
+++ b/cmd/gomobile/bind_test.go
@@ -175,7 +175,7 @@
 
 var bindAndroidTmpl = template.Must(template.New("output").Parse(`GOMOBILE={{.GOPATH}}/pkg/gomobile
 WORK=$WORK
-GOOS=android gobind -lang=go,java -outdir=$WORK{{if .JavaPkg}} -javapkg={{.JavaPkg}}{{end}} golang.org/x/mobile/asset
+GOOS=android CGO_ENABLED=1 gobind -lang=go,java -outdir=$WORK{{if .JavaPkg}} -javapkg={{.JavaPkg}}{{end}} golang.org/x/mobile/asset
 GOOS=android GOARCH=arm CC=$GOMOBILE/ndk-toolchains/arm/bin/arm-linux-androideabi-clang CXX=$GOMOBILE/ndk-toolchains/arm/bin/arm-linux-androideabi-clang++ CGO_ENABLED=1 GOARM=7 GOPATH=$WORK:$GOPATH go build -x -buildmode=c-shared -o=$WORK/android/src/main/jniLibs/armeabi-v7a/libgojni.so gobind
 PWD=$WORK/java javac -d $WORK/javac-output -source 1.7 -target 1.7 -bootclasspath {{.AndroidPlatform}}/android.jar *.java
 jar c -C $WORK/javac-output .
@@ -183,7 +183,7 @@
 
 var bindIOSTmpl = template.Must(template.New("output").Parse(`GOMOBILE={{.GOPATH}}/pkg/gomobile
 WORK=$WORK
-GOOS=darwin gobind -lang=go,objc -outdir=$WORK{{if .Prefix}} -prefix={{.Prefix}}{{end}} golang.org/x/mobile/asset
+GOOS=darwin CGO_ENABLED=1 gobind -lang=go,objc -outdir=$WORK -tags=ios{{if .Prefix}} -prefix={{.Prefix}}{{end}} golang.org/x/mobile/asset
 GOARM=7 GOOS=darwin GOARCH=arm CC=clang-iphoneos CXX=clang-iphoneos CGO_CFLAGS=-isysroot=iphoneos -miphoneos-version-min=6.1 -arch armv7 CGO_LDFLAGS=-isysroot=iphoneos -miphoneos-version-min=6.1 -arch armv7 CGO_ENABLED=1 GOPATH=$WORK:$GOPATH go build -tags ios -x -buildmode=c-archive -o $WORK/asset-arm.a gobind
 rm -r -f "Asset.framework"
 mkdir -p Asset.framework/Versions/A/Headers