thecl: Fix th15 ECL creation

This fixes issue #2.

Author: tirr-c

expr.c

@@ -108,7 +108,8 @@ expr_get_table(unsigned int version)
         && version != 128
         && version != 13
         && version != 14
-        && version != 143)
+        && version != 143
+        && version != 15)
         return NULL;
     return th10_expressions;
 }

thecl10.c

@@ -1596,7 +1596,8 @@ th10_instr_serialize(
         if (param->stack && (
                version == 13 || 
                version == 14 ||
-               version == 143
+               version == 143 ||
+               version == 15
            )
         ) {
             if (param->type == 'f' && param->value.val.f == -(ret->zero + 1.0f)) {