Allow libc++ to be built on systems without POSIX threads

If you're crazy enough to want this sort of thing, then add
-D_LIBCPP_HAS_NO_THREADS to your CXXFLAGS and
--param=additiona_features=libcpp-has-no-threads to your lit commnad line.

http://reviews.llvm.org/D3969

llvm-svn: 217271
diff --git a/libcxx/test/thread/thread.threads/thread.thread.this/get_id.pass.cpp b/libcxx/test/thread/thread.threads/thread.thread.this/get_id.pass.cpp
index ef6615b..3b4b782 100644
--- a/libcxx/test/thread/thread.threads/thread.thread.this/get_id.pass.cpp
+++ b/libcxx/test/thread/thread.threads/thread.thread.this/get_id.pass.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <thread>
 
diff --git a/libcxx/test/thread/thread.threads/thread.thread.this/sleep_for.pass.cpp b/libcxx/test/thread/thread.threads/thread.thread.this/sleep_for.pass.cpp
index f66b962..bffb5f3 100644
--- a/libcxx/test/thread/thread.threads/thread.thread.this/sleep_for.pass.cpp
+++ b/libcxx/test/thread/thread.threads/thread.thread.this/sleep_for.pass.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <thread>
 
diff --git a/libcxx/test/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp b/libcxx/test/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp
index 2f3bb9a..9f3941b 100644
--- a/libcxx/test/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp
+++ b/libcxx/test/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <thread>
 
diff --git a/libcxx/test/thread/thread.threads/thread.thread.this/yield.pass.cpp b/libcxx/test/thread/thread.threads/thread.thread.this/yield.pass.cpp
index 52f53a6..daf5b0c 100644
--- a/libcxx/test/thread/thread.threads/thread.thread.this/yield.pass.cpp
+++ b/libcxx/test/thread/thread.threads/thread.thread.this/yield.pass.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <thread>