Fix FreeBSD build after thread changes

More work on the GetName/SetName arguments (thread_t vs tid_t) is needed
but this change should restore the build and basic operation.

llvm-svn: 217502
diff --git a/lldb/source/Host/freebsd/ThisThread.cpp b/lldb/source/Host/freebsd/ThisThread.cpp
index 1c68c8b..a9f8058 100644
--- a/lldb/source/Host/freebsd/ThisThread.cpp
+++ b/lldb/source/Host/freebsd/ThisThread.cpp
@@ -13,6 +13,7 @@
 #include "llvm/ADT/SmallVector.h"
 
 #include <pthread.h>
+#include <pthread_np.h>
 
 using namespace lldb_private;
 
@@ -25,5 +26,5 @@
 void
 ThisThread::GetName(llvm::SmallVectorImpl<char> &name)
 {
-    HostNativeThread::GetName(::pthread_self(), name);
+    HostNativeThread::GetName(::pthread_getthreadid_np(), name);
 }