Revert "Change omitNeedlessWords to be based on ParameterList instead of TupleType."
Revert "Change omitNeedlessWords to be based on ParameterList instead of TupleType."

This reverts commit ccc1702a5d1cd77de119222449b45c5aa98ee5aa because it
breaks test/ClangModules/omit_needless_words.swift.

khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift