net: move into tokio crate (#1683)

A step towards collapsing Tokio sub crates into a single `tokio`
crate (#1318).

The `net` implementation is now provided by the main `tokio` crate.
Functionality can be opted out of by using the various net related
feature flags.

tests-build/tests/fail/executor_without_current_thread.rs

@@ -0,0 +1,3 @@
+use tests_build::tokio_executor::current_thread;
+
+fn main() {}

tests-build/tests/fail/executor_without_current_thread.stderr

@@ -0,0 +1,7 @@
+error[E0432]: unresolved import `tests_build::tokio_executor::current_thread`
+ --> $DIR/executor_without_current_thread.rs:1:5
+  |
+1 | use tests_build::tokio_executor::current_thread;
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `current_thread` in `tokio_executor`
+
+For more information about this error, try `rustc --explain E0432`.

tests-build/tests/fail/macros_invalid_input.rs

@@ -0,0 +1,25 @@
+use tests_build::tokio;
+
+#[tokio::main]
+fn main_is_not_async() {}
+
+#[tokio::main(foo)]
+async fn main_attr_has_unknown_args() {}
+
+#[tokio::main(threadpool::bar)]
+async fn main_attr_has_path_args() {}
+
+#[tokio::test]
+fn test_is_not_async() {}
+
+#[tokio::test]
+async fn test_fn_has_args(_x: u8) {}
+
+#[tokio::test(foo)]
+async fn test_attr_has_args() {}
+
+#[tokio::test]
+#[test]
+async fn test_has_second_test_attr() {}
+
+fn main() {}

tests-build/tests/fail/macros_invalid_input.stderr

@@ -0,0 +1,41 @@
+error: the async keyword is missing from the function declaration
+ --> $DIR/macros_invalid_input.rs:4:1
+  |
+4 | fn main_is_not_async() {}
+  | ^^
+
+error: Unknown attribute foo is specified; expected `current_thread` or `threadpool`
+ --> $DIR/macros_invalid_input.rs:6:15
+  |
+6 | #[tokio::main(foo)]
+  |               ^^^
+
+error: Must have specified ident
+ --> $DIR/macros_invalid_input.rs:9:15
+  |
+9 | #[tokio::main(threadpool::bar)]
+  |               ^^^^^^^^^^^^^^^
+
+error: the async keyword is missing from the function declaration
+  --> $DIR/macros_invalid_input.rs:13:1
+   |
+13 | fn test_is_not_async() {}
+   | ^^
+
+error: the test function cannot accept arguments
+  --> $DIR/macros_invalid_input.rs:16:27
+   |
+16 | async fn test_fn_has_args(_x: u8) {}
+   |                           ^^^^^^
+
+error: Unknown attribute foo is specified; expected `current_thread` or `threadpool`
+  --> $DIR/macros_invalid_input.rs:18:15
+   |
+18 | #[tokio::test(foo)]
+   |               ^^^
+
+error: second test attribute is supplied
+  --> $DIR/macros_invalid_input.rs:22:1
+   |
+22 | #[test]
+   | ^^^^^^^

tests-build/tests/fail/net_without_tcp_missing_tcp.rs

@@ -0,0 +1,4 @@
+use tests_build::tokio_net::tcp;
+
+fn main() {}
+

tests-build/tests/fail/net_without_tcp_missing_tcp.stderr

@@ -0,0 +1,7 @@
+error[E0432]: unresolved import `tests_build::tokio_net::tcp`
+ --> $DIR/net_without_tcp_missing_tcp.rs:1:5
+  |
+1 | use tests_build::tokio_net::tcp;
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `tcp` in `tokio_net`
+
+For more information about this error, try `rustc --explain E0432`.

tests-build/tests/fail/net_without_udp_missing_udp.rs

@@ -0,0 +1,4 @@
+use tests_build::tokio_net::udp;
+
+fn main() {}
+

tests-build/tests/fail/net_without_udp_missing_udp.stderr

@@ -0,0 +1,7 @@
+error[E0432]: unresolved import `tests_build::tokio_net::udp`
+ --> $DIR/net_without_udp_missing_udp.rs:1:5
+  |
+1 | use tests_build::tokio_net::udp;
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `udp` in `tokio_net`
+
+For more information about this error, try `rustc --explain E0432`.

tests-build/tests/fail/net_without_uds_missing_uds.rs

@@ -0,0 +1,4 @@
+use tests_build::tokio_net::uds;
+
+fn main() {}
+

tests-build/tests/fail/net_without_uds_missing_uds.stderr

@@ -0,0 +1,7 @@
+error[E0432]: unresolved import `tests_build::tokio_net::uds`
+ --> $DIR/net_without_uds_missing_uds.rs:1:5
+  |
+1 | use tests_build::tokio_net::uds;
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `uds` in `tokio_net`
+
+For more information about this error, try `rustc --explain E0432`.

tests-build/tests/fail/tokio_without_net_missing_net.rs

@@ -0,0 +1,3 @@
+use tests_build::tokio::net;
+
+fn main() {}

tests-build/tests/fail/tokio_without_net_missing_net.stderr

@@ -0,0 +1,7 @@
+error[E0432]: unresolved import `tests_build::tokio::net`
+ --> $DIR/tokio_without_net_missing_net.rs:1:5
+  |
+1 | use tests_build::tokio::net;
+  |     ^^^^^^^^^^^^^^^^^^^^^^^ no `net` in `tokio`
+
+For more information about this error, try `rustc --explain E0432`.