[android] Fix some tests and a doc flag

Use off_t for a recently failing stdlib test, remove Python hacks for some
tests that now work without them, and correct build flag in the docs.

Author: finagolfin

docs/Android.md

@@ -161,5 +161,5 @@ $ utils/build-script \
   --android \                        # Build for Android.
   --android-ndk ~/android-ndk-r23b \  # Path to an Android NDK.
   --android-arch armv7 \             # Optionally specify Android architecture, alternately aarch64
-  --android-ndk-version 21
+  --android-api-level 21
 ```

test/lit.cfg

@@ -1438,9 +1438,6 @@ elif (run_os in ['linux-gnu', 'linux-gnueabihf', 'freebsd', 'openbsd', 'windows-
       config.target_shared_library_prefix = 'lib'
       config.target_shared_library_suffix = ".so"
       config.target_sdk_name = "android"
-      # Needed by several ParseableInterface/swift_build_sdk_interfaces tests on
-      # Android
-      config.environment['ANDROID_DATA'] = os.environ['ANDROID_DATA']
       config.target_cc_options = "-fPIE"
     else:
       lit_config.note("Testing Linux " + config.variant_triple)

test/stdlib/POSIX.swift

@@ -246,13 +246,7 @@ POSIXTests.test("fcntl(CInt, CInt, UnsafeMutableRawPointer): locking and unlocki
   // Lock for reading...
   var flck = flock()
   flck.l_type = Int16(F_RDLCK)
-  #if os(Android)
-  // In Android l_len is __kernel_off_t which is not the same size as off_t in
-  // 64 bits.
-  flck.l_len = __kernel_off_t(data.utf8.count)
-  #else
   flck.l_len = off_t(data.utf8.count)
-  #endif
   rc = fcntl(fd, F_SETLK, &flck)
   expectEqual(0, rc)
 

utils/swift_build_sdk_interfaces.py

@@ -410,18 +410,9 @@ def main():
     # Copy a file containing SDK build version into the prebuilt module dir,
     # so we can keep track of the SDK version we built from.
     copySystemVersionFile(args.sdk, args.output_dir)
-    if 'ANDROID_DATA' not in os.environ:
-        shared_output_lock = multiprocessing.Lock()
-        pool = multiprocessing.Pool(args.jobs, set_up_child,
-                                    (args, shared_output_lock))
-    else:
-        # Android doesn't support Python's multiprocessing as it doesn't have
-        # sem_open, so switch to a ThreadPool instead.
-        import threading
-        shared_output_lock = threading.Lock()
-        from multiprocessing.pool import ThreadPool
-        pool = ThreadPool(args.jobs, set_up_child,
-                          (args, shared_output_lock))
+    shared_output_lock = multiprocessing.Lock()
+    pool = multiprocessing.Pool(args.jobs, set_up_child,
+                                (args, shared_output_lock))
 
     interface_framework_dirs = (args.interface_framework_dirs or
                                 DEFAULT_FRAMEWORK_INTERFACE_SEARCH_PATHS)