Silenced some warnings about comparison between signed and unsigned integer
expressions.
Issue #22221: Add tests for compile() with source encoding cookie.

--HG--
branch : 3.4
Issue #22221: Add tests for compile() with source encoding cookie.
Issue #20643: Removed unneeded (and wrong) class directives.

--HG--
branch : 3.4
Issue #20643: Removed unneeded (and wrong) class directives.
Keep Mac/build-installer.py in sync across branches (affects 2.7 only).

--HG--
branch : 3.4
Keep Mac/build-installer.py in sync across branches (affects 2.7 only).