Use clippy (#276)

* cton-util: fix some clippy unnecessary pass-by-value warnings

* clippy: ignore too many arguments / cyclomatic complexity in module

since these functions are taking args coming from the command line, i
dont think this is actually a valid lint, morally the arguments are all
from one structure

* cton-util: take care of remaining clippy warnings

* cton-reader: fix all non-suspicious clippy warnings

* cton-reader: disable clippy at site of suspicious lint

* cton-frontend: disable clippy at the site of an invalid lint

* cton-frontend: fix clippy warnings, or ignore benign ones

* clippy: ignore the camelcase word WebAssembly in docs

* cton-wasm: fix clippy complaints or ignore benign ones

* cton-wasm tests: fix clippy complaints

* cretonne: starting point turns off all clippy warnings

* cretonne: clippy fixes, or lower allow() to source of problem

* cretonne: more clippy fixes

* cretonne: fix or disable needless_lifetimes lint

this linter is buggy when the declared lifetime is used for another type
constraint.

* cretonne: fix clippy complaint about Pass::NoPass

* rustfmt

* fix prev minor api changes clippy suggested

* add clippy to test-all

* cton-filetests: clippy fixes

* simplify clippy reporting in test-all

* cretonne: document clippy allows better

* cretonne: fix some more clippy lints

* cretonne: fix clippy lints (mostly doc comments)

* cretonne: allow all needless_lifetimes clippy warnings

remove overrides at the false positives

* rustfmt

lib/cretonne/src/context.rs

@@ -132,12 +132,12 @@ impl Context {
     }
 
     /// Run the locations verifier on the function.
-    pub fn verify_locations<'a>(&self, isa: &TargetIsa) -> verifier::Result {
+    pub fn verify_locations(&self, isa: &TargetIsa) -> verifier::Result {
         verifier::verify_locations(isa, &self.func, None)
     }
 
     /// Run the locations verifier only if the `enable_verifier` setting is true.
-    pub fn verify_locations_if<'a>(&self, isa: &TargetIsa) -> CtonResult {
+    pub fn verify_locations_if(&self, isa: &TargetIsa) -> CtonResult {
         if isa.flags().enable_verifier() {
             self.verify_locations(isa).map_err(Into::into)
         } else {