arm: add gdb support to android launcher script

R=rsc
CC=golang-dev
https://golang.org/cl/1742050

misc/arm/a

@@ -39,11 +39,20 @@ echo RETVAL: $?'
 fi
 
 # run the main binary
-if [ "$*" != "$1" ]; then
-	args=$(echo $*| cut -d' ' -f2-)
+if [ "-g" == "$1" ]; then
+	adb forward tcp:$2 tcp:$2
+	args=$(echo $*| cut -d' ' -f4-)
+	adb push $3 /data/local/tmp/$3 >/dev/null 2>&1
+	adb shell "$(exp GOARCH) $(exp GOTRACEBACK) $(exp GOGC) \
+		gdbserver :$2 /data/local/tmp/retval /data/local/tmp/$3 $args" \
+		2>&1|tr -d '\r' |tee /tmp/adb.out|grep -v RETVAL
+else
+	if [ "$*" != "$1" ]; then
+		args=$(echo $*| cut -d' ' -f2-)
+	fi
+	adb push $1 /data/local/tmp/$1 >/dev/null 2>&1
+	adb shell "$(exp GOARCH) $(exp GOTRACEBACK) $(exp GOGC) \
+		/data/local/tmp/retval /data/local/tmp/$1 $args" \
+		2>&1|tr -d '\r' |tee /tmp/adb.out|grep -v RETVAL
 fi
-adb push $1 /data/local/tmp/$1 >/dev/null 2>&1
-adb shell "$(exp GOARCH) $(exp GOTRACEBACK) $(exp GOGC) \
-	/data/local/tmp/retval /data/local/tmp/$1 $args" \
-	2>&1|tr -d '\r' |tee /tmp/adb.out|grep -v RETVAL
 exit $(grep RETVAL /tmp/adb.out|tr -d '\n\r'| cut -d' ' -f2)