Support ARM and Android

Conflicts:
	src/libcore/os.rs
	src/librustc/back/link.rs
	src/librustc/driver/driver.rs
	src/librustc/metadata/loader.rs
	src/librustc/middle/trans/base.rs

src/rt/rust_builtin.cpp

@@ -33,6 +33,27 @@
 extern char **environ;
 #endif
 
+#ifdef __ANDROID__
+time_t
+timegm(struct tm *tm)
+{
+    time_t ret;
+    char *tz;
+
+    tz = getenv("TZ");
+    setenv("TZ", "", 1);
+    tzset();
+    ret = mktime(tm);
+    if (tz)
+        setenv("TZ", tz, 1);
+    else
+        unsetenv("TZ");
+    tzset();
+    return ret;
+}
+#endif
+
+
 extern "C" CDECL rust_str*
 last_os_error() {
     rust_task *task = rust_get_current_task();