Build fix for systems that do not support NT_X86_XSTATE ptrace support.

Patch by Ashok Thirumurthi.

llvm-svn: 180581

lldb/source/Plugins/Process/POSIX/RegisterContext_x86_64.cpp

@@ -28,6 +28,11 @@
 using namespace lldb_private;
 using namespace lldb;
 
+// Support ptrace extensions even when compiled without required kernel support
+#ifndef NT_X86_XSTATE
+  #define NT_X86_XSTATE 0x202
+#endif
+
 // Internal codes for all x86_64 registers.
 enum
 {