Auto merge of #29546 - alexcrichton:new-libc, r=brson

This commit replaces the in-tree liblibc with the [external clone](https://github.com/rust-lang-nursery/libc) which has no evolved beyond the in-tree version in light of its [recent redesign](https://github.com/rust-lang/rfcs/pull/1291).

The primary changes here are:

* `src/liblibc/lib.rs` was deleted
* `src/liblibc` is now a submodule pointing at the external repository
* `src/libstd/sys/unix/{c.rs,sync.rs}` were both deleted having all bindings folded into the external liblibc.
* Many ad-hoc `extern` blocks in the standard library were removed in favor of bindings now being in the external liblibc.
* Many functions/types were added to `src/libstd/sys/windows/c.rs`, and the scattered definitions throughout the standard library were consolidated here.

At the API level this commit is **not a breaking change**, although it is only very lightly tested on the *BSD variants and is probably going to break almost all of their builds! Follow-up commits to liblibc should in theory be all that's necessary to get the build working on the *BSDs again.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/libstd/sys/windows/stack_overflow.rs b/src/libstd/sys/windows/stack_overflow.rs
index d1c2144ef0d..01317bec0de 100644
--- a/src/libstd/sys/windows/stack_overflow.rs
+++ b/src/libstd/sys/windows/stack_overflow.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use libc::{self, LONG};
 use sys_common::util::report_overflow;
 use sys::c;
 
@@ -19,7 +18,7 @@ impl Handler {
         // This API isn't available on XP, so don't panic in that case and just
         // pray it works out ok.
         if c::SetThreadStackGuarantee(&mut 0x5000) == 0 {
-            if libc::GetLastError() as u32 != libc::ERROR_CALL_NOT_IMPLEMENTED as u32 {
+            if c::GetLastError() as u32 != c::ERROR_CALL_NOT_IMPLEMENTED as u32 {
                 panic!("failed to reserve stack space for exception handling");
             }
         }
@@ -28,7 +27,7 @@ impl Handler {
 }
 
 extern "system" fn vectored_handler(ExceptionInfo: *mut c::EXCEPTION_POINTERS)
-                                    -> LONG {
+                                    -> c::LONG {
     unsafe {
         let rec = &(*(*ExceptionInfo).ExceptionRecord);
         let code = rec.ExceptionCode;