Detect HAVE_SYS_TYPES_H in lldb

Summary:
After rL368069 I noticed that HAVE_SYS_TYPES_H is not defined in
Platform.h, or anywhere else in lldb. This change fixes that.

Reviewers: labath

Subscribers: mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D65822

llvm-svn: 368125
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
index 91f333f..54d852b 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "lldb/Host/Config.h"
+
 #include <stdio.h>
 #if HAVE_SYS_TYPES_H
 #include <sys/types.h>