Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/autocfg/examples/integers.rs

@@ -0,0 +1,9 @@
+extern crate autocfg;
+
+fn main() {
+    // Normally, cargo will set `OUT_DIR` for build scripts.
+    let ac = autocfg::AutoCfg::with_dir("target").unwrap();
+    for i in 3..8 {
+        ac.emit_has_type(&format!("i{}", 1 << i));
+    }
+}

vendor/autocfg/examples/paths.rs

@@ -0,0 +1,22 @@
+extern crate autocfg;
+
+fn main() {
+    // Normally, cargo will set `OUT_DIR` for build scripts.
+    let ac = autocfg::AutoCfg::with_dir("target").unwrap();
+
+    // since ancient times...
+    ac.emit_has_path("std::vec::Vec");
+    ac.emit_path_cfg("std::vec::Vec", "has_vec");
+
+    // rustc 1.10.0
+    ac.emit_has_path("std::panic::PanicInfo");
+    ac.emit_path_cfg("std::panic::PanicInfo", "has_panic_info");
+
+    // rustc 1.20.0
+    ac.emit_has_path("std::mem::ManuallyDrop");
+    ac.emit_path_cfg("std::mem::ManuallyDrop", "has_manually_drop");
+
+    // rustc 1.25.0
+    ac.emit_has_path("std::ptr::NonNull");
+    ac.emit_path_cfg("std::ptr::NonNull", "has_non_null");
+}

vendor/autocfg/examples/traits.rs

@@ -0,0 +1,26 @@
+extern crate autocfg;
+
+fn main() {
+    // Normally, cargo will set `OUT_DIR` for build scripts.
+    let ac = autocfg::AutoCfg::with_dir("target").unwrap();
+
+    // since ancient times...
+    ac.emit_has_trait("std::ops::Add");
+    ac.emit_trait_cfg("std::ops::Add", "has_ops");
+
+    // trait parameters have to be provided
+    ac.emit_has_trait("std::borrow::Borrow<str>");
+    ac.emit_trait_cfg("std::borrow::Borrow<str>", "has_borrow");
+
+    // rustc 1.8.0
+    ac.emit_has_trait("std::ops::AddAssign");
+    ac.emit_trait_cfg("std::ops::AddAssign", "has_assign_ops");
+
+    // rustc 1.12.0
+    ac.emit_has_trait("std::iter::Sum");
+    ac.emit_trait_cfg("std::iter::Sum", "has_sum");
+
+    // rustc 1.28.0
+    ac.emit_has_trait("std::alloc::GlobalAlloc");
+    ac.emit_trait_cfg("std::alloc::GlobalAlloc", "has_global_alloc");
+}

vendor/autocfg/examples/versions.rs

@@ -0,0 +1,9 @@
+extern crate autocfg;
+
+fn main() {
+    // Normally, cargo will set `OUT_DIR` for build scripts.
+    let ac = autocfg::AutoCfg::with_dir("target").unwrap();
+    for i in 0..100 {
+        ac.emit_rustc_version(1, i);
+    }
+}