[tests] refactor tests to simplify future changes

tests/constant_propagation/array_pointers.i

 /* run.config
-   OPT: -eva -eva-show-progress -scf -eva-show-progress -journal-disable
+   STDOPT: +"-eva"
 */
 
 void *p;

tests/constant_propagation/bts-1787-bis.i

 /* run.config
-OPT: -journal-disable -print
-OPT: -journal-disable -scf -eva-show-progress
-OPT: -journal-disable -scf -eva-show-progress -scf-allow-cast
+   OPT: -print -journal-disable
+   STDOPT:
+   STDOPT: +"-scf-allow-cast"
 */
 
 typedef struct {

tests/constant_propagation/bts-1787.i

 /* run.config
-OPT: -journal-disable -scf -eva-show-progress -scf-allow-cast
-OPT: -journal-disable -scf -eva-show-progress
+   STDOPT: +"-scf-allow-cast"
+   STDOPT:
 */
 
 typedef struct {

tests/constant_propagation/const_field_return_struct.i

 /* run.config
-   OPT: -eva -eva-show-progress -scf -eva-show-progress -journal-disable
+   STDOPT: +"-eva"
 */
 
 struct S {

tests/constant_propagation/enum.i

 /* run.config
-OPT: -semantic-const-folding -eva-show-progress
+   STDOPT:
 */
 
 enum E { A, B, C, D };

tests/constant_propagation/fct_ptr.i

 /* run.config
-OPT: -scf -eva-show-progress -then-on propagated
+   STDOPT: +"-then-on propagated"
 */
 
 void (*pf)(void);

tests/constant_propagation/struct_field.i

 /* run.config
-   OPT: -eva -semantic-const-folding -eva-show-progress -journal-disable
+   STDOPT: +"-eva"
 */
 
 struct st {

tests/constant_propagation/test_config

+OPT: -journal-disable -scf -eva-show-progress