Provide location by default

This makes the definition of the passes slightly cleaner.
Cleanup the first pass (fold_pass)
Cleanup next pass
Cleanup purity-letref
Cleanup elim-times
Cleanup letfunc
Cleanup letfun-times
Cleanup times-unroll
Cleanup inline
Typo
Cleanup push-comp-locals
Cleanup take-emit
Cleanup float-letfun-repeat
Cleanup float-let-par
Cleanup ifdead
Cleanup if-return