export-file-local-symbols: handling files with many functions

The use of --export-file-local-symbols entails renaming of file-local
(function) symbols with a prefix of __CPROVER_file_local, which had the
side effect of those names being added as defines when building hybrid
binaries. For files with large numbers of static functions, this
resulted in a command-line that exceeds operating-system limits.

Author: tautschnig

src/goto-cc/compile.cpp

@@ -748,6 +748,9 @@ bool compilet::add_written_cprover_symbols(const symbol_tablet &symbol_table)
     if(!(has_prefix(id2string(name), CPROVER_PREFIX) && new_type.id()==ID_code))
       continue;
 
+    if(has_prefix(id2string(name), FILE_LOCAL_PREFIX))
+      continue;
+
     bool inserted;
     std::map<irep_idt, symbolt>::iterator old;
     std::tie(old, inserted)=written_macros.insert({name, pair.second});