Add missing static

This ensures the function is only used within the cpp file where it is
defined. This should be used for all functions which are not part of the
interface in the header file.

Author: romainbrenguier

src/goto-symex/build_goto_trace.cpp

@@ -25,7 +25,7 @@ Author: Daniel Kroening
 
 #include "partial_order_concurrency.h"
 
-exprt build_full_lhs_rec(
+static exprt build_full_lhs_rec(
   const prop_convt &prop_conv,
   const namespacet &ns,
   const exprt &src_original, // original identifiers
@@ -104,7 +104,7 @@ exprt build_full_lhs_rec(
 
 /// set internal field for variable assignment related to dynamic_object[0-9]
 /// and dynamic_[0-9]_array.
-void set_internal_dynamic_object(
+static void set_internal_dynamic_object(
   const exprt &expr,
   goto_trace_stept &goto_trace_step,
   const namespacet &ns)
@@ -132,7 +132,7 @@ void set_internal_dynamic_object(
 
 /// set internal for variables assignments related to dynamic_object and CPROVER
 /// internal functions (e.g., __CPROVER_initialize)
-void update_internal_field(
+static void update_internal_field(
   const symex_target_equationt::SSA_stept &SSA_step,
   goto_trace_stept &goto_trace_step,
   const namespacet &ns)