Fixed all -Wincompatible-pointer-types-discards-qualifiers warnings (#341)

* Fixed various -Wincompatible-pointer-types-discards-qualifiers warnings by adding const

* Fixed various -Wincompatible-pointer-types-discards-qualifiers warning by removing extraneous consts

There were casts with const, but the function parameter doesn't actaully take const, so just modified the casts.

In the other case, a local variable was const that should not have been, becuase its source wasn't const either.

* Fixed a -Wincompatible-pointer-types-discards-qualifiers warning by strdup-ing a string

Create a duplicate string instead of mutating a supposedly const one.

path: root/Lib/test/test_longexp.py

REPS = 65580

l = eval("[" + "2," * REPS + "]")
print len(l)