predicate.py: Add an option to not delete temp files
predicate.py: Add an option to not delete temp files

Useful when debugging.

rust-lang/rust-bindgen,emilio/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,emilio/rust-bindgen