Deprecate has_symbol

This code does not permit configuration what kinds of symbols are to be
found. It had a single user within the code base, and even that one was
not a good use of it for it constructed a single-element set.

Author: tautschnig

src/ansi-c/goto_check_c.cpp

@@ -461,12 +461,12 @@ void goto_check_ct::invalidate(const exprt &lhs)
   else if(lhs.id() == ID_symbol)
   {
     // clear all assertions about 'symbol'
-    find_symbols_sett find_symbols_set{to_symbol_expr(lhs).get_identifier()};
+    const irep_idt &lhs_id = to_symbol_expr(lhs).get_identifier();
 
     for(auto it = assertions.begin(); it != assertions.end();)
     {
       if(
-        has_symbol(it->second, find_symbols_set) ||
+        find_symbol_identifiers(it->second).count(lhs_id) != 0 ||
         has_subexpr(it->second, ID_dereference))
       {
         it = assertions.erase(it);

src/util/find_symbols.h

@@ -10,12 +10,13 @@ Author: Daniel Kroening, [email protected]
 #ifndef CPROVER_UTIL_FIND_SYMBOLS_H
 #define CPROVER_UTIL_FIND_SYMBOLS_H
 
+#include "deprecate.h"
+#include "irep.h"
+
 #include <algorithm>
 #include <set>
 #include <unordered_set>
 
-#include "irep.h"
-
 class exprt;
 class symbol_exprt;
 class typet;
@@ -59,6 +60,7 @@ std::set<symbol_exprt> find_symbols(const exprt &src);
 /// Find identifiers of the sub expressions with id ID_symbol
 std::unordered_set<irep_idt> find_symbol_identifiers(const exprt &src);
 
+DEPRECATED(SINCE(2022, 3, 14, "pick a specific implementation of find_symbols"))
 /// \return true if one of the symbols in \p src is present in \p symbols
 bool has_symbol(
   const exprt &src,