tools/remote-test-{server,client}: Use /data/local/tmp on Android

The /data/tmp directory does not exist, at least not on recent versions
of Android, which currently leads to test failures on that platform. I
checked a virtual device running AOSP master and a Nexus 5 running
Android Marshmallow and on both devices the /data/tmp directory does
not exist and /data/local/tmp does, so let's switch to /data/local/tmp.

src/bootstrap/test.rs

@@ -23,7 +23,7 @@
 use crate::util::{self, add_link_lib_path, dylib_path, dylib_path_var, output, t};
 use crate::{envify, CLang, DocTests, GitRepo, Mode};
 
-const ADB_TEST_DIR: &str = "/data/tmp/work";
+const ADB_TEST_DIR: &str = "/data/local/tmp/work";
 
 /// The two modes of the test runner; tests or benchmarks.
 #[derive(Debug, PartialEq, Eq, Hash, Copy, Clone, PartialOrd, Ord)]

src/tools/remote-test-client/src/main.rs

@@ -93,7 +93,7 @@ fn start_android_emulator(server: &Path) {
 
     println!("pushing server");
     let status =
-        Command::new("adb").arg("push").arg(server).arg("/data/tmp/testd").status().unwrap();
+        Command::new("adb").arg("push").arg(server).arg("/data/local/tmp/testd").status().unwrap();
     assert!(status.success());
 
     println!("forwarding tcp");
@@ -102,7 +102,7 @@ fn start_android_emulator(server: &Path) {
     assert!(status.success());
 
     println!("executing server");
-    Command::new("adb").arg("shell").arg("/data/tmp/testd").spawn().unwrap();
+    Command::new("adb").arg("shell").arg("/data/local/tmp/testd").spawn().unwrap();
 }
 
 fn prepare_rootfs(target: &str, rootfs: &Path, server: &Path, rootfs_img: &Path) {

src/tools/remote-test-server/src/main.rs

@@ -98,7 +98,7 @@ fn main() {
 
     let listener = t!(TcpListener::bind(config.bind));
     let (work, tmp): (PathBuf, PathBuf) = if cfg!(target_os = "android") {
-        ("/data/tmp/work".into(), "/data/tmp/work/tmp".into())
+        ("/data/local/tmp/work".into(), "/data/local/tmp/work/tmp".into())
     } else {
         let mut work_dir = env::temp_dir();
         work_dir.push("work");