Add CPython tempfile + tests
tempfile: Remove conditional import
tempfile: Remove attribute 'del'
tempfile: Refactor local variable 'del'
tempfile: Refactor conditional function def

Also remove conditional import.
tempfile: Refactor conditional method definitions
tempfile: Remove CPython-specific code
tempfile: Refactor property
tempfile: Comment out properties
tempfile: Refactor raise with type object
tempfile: Add 'any' type annotations
tempfile: Refactor reference to os.sys
tempfile: Refactor conditional module attr lookups
Update _thread stubs
Fix os.lstat stub signature
Add minimal fcntl stubs
Support raise without argument (fix #134)
Revert "test.support: Work around front end bug"

This reverts commit c77dbb189b7bab5e6f2a6087c45280c5ec4f39e6.
Implement parsing of set literal with type prefix
Implement type checking set literals (close #148)