WL#6983: Migrate funcs_2 suite to run with InnoDB

All the testcases in the suite "funcs_2", should run with InnoDB engine.

Implementation deatils:
-----------------------
1) Look at the each testcase in the suite
2) check whether it is related to InnoDB or Myisam 
Ex: create table tab1(c1 int) Engine=Myisam;

3) If it is Myisam related testcase then retain the inc file :
force_myisam_default.inc

4) if the testcase is related to InnoDB or any other engines , should run with
InnoDB is a default storage engine.

5) Check the result of the testcase 

Note: some times the result file may differ when running with InnoDB engine, for
those cases the result files have to be recorded, But it depends on the case by
case.

Funcs_2:
--------
The following are the changes made to the tescases.

1. memory_charset.test: Removed this line : --source
include/force_myisam_default.inc from the testcase
2. myisam_charset.test: Added the comments saying that, This is a myisam based
testcase hence retained the following line.

No other changes are made into the testcase files or result files.