testing various combinations of displaying variales of basic types.

The generic_type_tester() works by first capturing the golden output produced
by the printf stmts of ./a.out, creating a list of (var, value) pairs, and then
running the a.out to a stop point, and comparing the 'frame variable var' output
against the list of (var, value) pairs.

Modified int_type() and added long_type() to use generic_type_tester().

Also modified TestBase.expect() such that substring matching also return ok if
the substring starts at the 0-th position.

llvm-svn: 114708