Merge pull request #6764 from tautschnig/cleanup/functional

Add missing <functional> include [blocks: #6749]

Author: kroening

src/goto-programs/resolve_inherited_component.h

@@ -16,6 +16,8 @@ Author: Diffblue Ltd.
 #include <util/irep.h>
 #include <util/optional.h>
 
+#include <functional>
+
 class symbolt;
 class symbol_tablet;
 

src/solvers/flattening/boolbv_map.h

@@ -10,12 +10,13 @@ Author: Daniel Kroening, [email protected]
 #ifndef CPROVER_SOLVERS_FLATTENING_BOOLBV_MAP_H
 #define CPROVER_SOLVERS_FLATTENING_BOOLBV_MAP_H
 
-#include <iosfwd>
-
 #include <util/type.h>
 
 #include <solvers/prop/literal.h>
 
+#include <functional>
+#include <iosfwd>
+
 class propt;
 
 class boolbv_mapt

src/util/expr.h

@@ -15,6 +15,8 @@ Author: Daniel Kroening, [email protected]
 #include "validate_types.h"
 #include "validation_mode.h"
 
+#include <functional>
+
 #define forall_operands(it, expr)                                              \
   for(exprt::operandst::const_iterator                                         \
         it = as_const(expr).operands().begin(),                                \