Don't #include ClangPersistentVariables.h from Process.h

Nothing from this header file was even being referenced in
Process.h anyway, so it was a completely unnecessary include.

llvm-svn: 231131
diff --git a/lldb/source/Expression/ClangUserExpression.cpp b/lldb/source/Expression/ClangUserExpression.cpp
index 5514846..1ce5049 100644
--- a/lldb/source/Expression/ClangUserExpression.cpp
+++ b/lldb/source/Expression/ClangUserExpression.cpp
@@ -26,6 +26,7 @@
 #include "lldb/Expression/ClangExpressionDeclMap.h"
 #include "lldb/Expression/ClangExpressionParser.h"
 #include "lldb/Expression/ClangFunction.h"
+#include "lldb/Expression/ClangPersistentVariables.h"
 #include "lldb/Expression/ClangUserExpression.h"
 #include "lldb/Expression/ExpressionSourceCode.h"
 #include "lldb/Expression/IRExecutionUnit.h"