Add missing include.

The delete param.second needs the full definition of
struct AstNode.

Signed-off-by: Henner Zeller <hzeller@google.com>

systemverilog-plugin/uhdmastshared.h

diff --git a/systemverilog-plugin/uhdmastshared.h b/systemverilog-plugin/uhdmastshared.h
index 36a1068..5ea5d22 100644
--- a/systemverilog-plugin/uhdmastshared.h
+++ b/systemverilog-plugin/uhdmastshared.h
@@ -1,6 +1,8 @@
 #ifndef _UHDM_AST_SHARED_H_
 #define _UHDM_AST_SHARED_H_ 1
 
+#include "frontends/ast/ast.h"
+
 #include "uhdmastreport.h"
 #include <string>
 #include <unordered_map>