Add a few missing headers

Fixes build with gcc 4.3.2

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
diff --git a/tools/aidl/generate_java.cpp b/tools/aidl/generate_java.cpp
index 7f84ff4..affac0f 100644
--- a/tools/aidl/generate_java.cpp
+++ b/tools/aidl/generate_java.cpp
@@ -1,6 +1,7 @@
 #include "generate_java.h"
 #include "AST.h"
 #include "Type.h"
+#include <string.h>
 #include <stdio.h>
 
 // =================================================