Auto merge of #21959 - dhuseby:bitrig-support, r=brson

This patch adds the necessary pieces to support rust on Bitrig https://bitrig.org

diff --cc configure
Simple merge

diff --cc src/compiletest/util.rs
Simple merge

diff --cc src/doc/reference.md
Simple merge

diff --cc src/liblibc/lib.rs
Simple merge

diff --cc src/librustc_back/rpath.rs
Simple merge

diff --cc src/librustc_back/target/mod.rs
Simple merge

diff --cc src/librustdoc/flock.rs
Simple merge

diff --cc src/libstd/dynamic_lib.rs
Simple merge

diff --cc src/libstd/env.rs
Simple merge

diff --cc src/libstd/os.rs
Simple merge

diff --cc src/libstd/rt/args.rs
Simple merge

diff --cc src/libstd/sys/common/net.rs
Simple merge

diff --cc src/libstd/sys/unix/backtrace.rs
Simple merge

diff --cc src/libstd/sys/unix/c.rs
Simple merge

diff --cc src/libstd/sys/unix/fs.rs
Simple merge

diff --cc src/libstd/sys/unix/os.rs
Simple merge

diff --cc src/libstd/sys/unix/process.rs
Simple merge

diff --cc src/libstd/sys/unix/thread.rs
index c90ba7645feb4b29f14a6b6854804c6d79d617e9,ae9261d87c6a5975446dcc3a029f1b8f147ca0b3..c42d6d0e6416cef66b779371cb6a313c9530a826
--- 1/src/libstd/sys/unix/thread.rs
--- 2/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@@ -190,9 -194,25 +195,25 @@@ pub mod guard 
  
          stackaddr as uint + guardsize as uint
      }
+ 
+     #[cfg(target_os = "bitrig")]
+     pub unsafe fn current() -> uint {
+       let mut current_stack: stack_t = mem::zeroed();
+       if pthread_stackseg_np(pthread_self(), &mut current_stack) != 0 {
+         panic!("failed to get current stack: pthread_stackseg_np")
+       }
+ 
+       if pthread_main_np() == 1 {
+         // main thread
+         current_stack.ss_sp as uint - current_stack.ss_size as uint + 3 * PAGE_SIZE as uint
+       } else {
+         // new thread
+         current_stack.ss_sp as uint - current_stack.ss_size as uint
+       }
+     }
  }
  
 -pub unsafe fn create(stack: uint, p: Thunk) -> rust_thread {
 +pub unsafe fn create(stack: uint, p: Thunk) -> io::Result<rust_thread> {
      let mut native: libc::pthread_t = mem::zeroed();
      let mut attr: libc::pthread_attr_t = mem::zeroed();
      assert_eq!(pthread_attr_init(&mut attr), 0);

diff --cc src/test/run-pass/intrinsic-alignment.rs
Simple merge

diff --cc src/test/run-pass/out-of-stack-new-thread-no-split.rs
Simple merge

diff --cc src/test/run-pass/out-of-stack-no-split.rs
Simple merge

diff --cc src/test/run-pass/rec-align-u64.rs
Simple merge

diff --cc src/test/run-pass/x86stdcall.rs
Simple merge