Put undefined symbols in separate table.

Even though all regression tests pass, it feels better to do the
undefined symbols similar to the implicit globals.

assemble_aux.c

@@ -213,8 +213,9 @@ void implicit_gbl(
                     /* Either make the undefined symbol into an implicit global */
                     add_sym(value->data.symbol->label, 0, SYMBOLFLAG_GLOBAL, &absolute_section, &implicit_st);
                 } else {
-                    /* or add it to the symbol table, purely for listing purposes. */
-                    add_sym(value->data.symbol->label, 0, SYMBOLFLAG_UNDEFINED, &absolute_section, &symbol_st);
+                    /* or add it to the undefined symbol table,
+                       purely for listing purposes. */
+                    add_sym(value->data.symbol->label, 0, SYMBOLFLAG_UNDEFINED, &absolute_section, &undefined_st);
                 }
             }
         }
@@ -265,6 +266,28 @@ void migrate_implicit(
     }
 }
 
+/* Done between second pass and listing */
+/* Migrates the symbols from the "undefined" table into the main table. */
+
+void migrate_undefined(
+    void)
+{
+    SYMBOL_ITER     iter;
+    SYMBOL         *isym,
+                   *sym;
+
+    for (isym = first_sym(&undefined_st, &iter); isym != NULL; isym = next_sym(&undefined_st, &iter)) {
+        sym = lookup_sym(isym->label, &symbol_st);
+        if (sym) {
+            continue;                  /* It's already in there.  Great. */
+        }
+        isym->flags |= SYMBOLFLAG_UNDEFINED; /* Just in case */
+        sym = add_sym(isym->label, isym->value, isym->flags, isym->section, &symbol_st);
+        /* Just one other thing - migrate the stmtno */
+        sym->stmtno = isym->stmtno;
+    }
+}
+
 int express_sym_offset(
     EX_TREE *value,
     SYMBOL **sym,

assemble_aux.h

@@ -85,7 +85,7 @@ void            write_globals(
     FILE *obj);
 void            migrate_implicit(
     void);
-
-
+void            migrate_undefined(
+    void);
 
 #endif

macro11.c

@@ -417,6 +417,7 @@ int main(
         fprintf(stderr, "%d Errors\n", errcount);
 
     if (lstfile) {
+        migrate_undefined();           /* Migrate the undefined symbols */
         list_symbol_table();
     }
 

symbols.c

@@ -30,6 +30,8 @@ SYMBOL_TABLE    macro_st;       /* Macros */
 
 SYMBOL_TABLE    implicit_st;    /* The symbols which may be implicit globals */
 
+SYMBOL_TABLE    undefined_st;   /* The symbols which may be undefined */
+
 
 void list_section(SECTION *sec);
 

symbols.h

@@ -370,6 +370,8 @@ extern SYMBOL_TABLE macro_st;   /* Macros */
 
 extern SYMBOL_TABLE implicit_st;        /* The symbols which may be implicit globals */
 
+extern SYMBOL_TABLE undefined_st;       /* The symbols which may be undefined */
+
 #endif
 
 int             hash_name(