slighty simplify a few boolean expressions (clippy::nonminimal_bool)

compiler/rustc_const_eval/src/transform/validate.rs

@@ -677,8 +677,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     );
                 }
                 if let Rvalue::CopyForDeref(place) = rvalue {
-                    if !place.ty(&self.body.local_decls, self.tcx).ty.builtin_deref(true).is_some()
-                    {
+                    if place.ty(&self.body.local_decls, self.tcx).ty.builtin_deref(true).is_none() {
                         self.fail(
                             location,
                             "`CopyForDeref` should only be used for dereferenceable types",

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -559,7 +559,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
                 // struct; however, when EUV is run during typeck, it
                 // may not. This will generate an error earlier in typeck,
                 // so we can just ignore it.
-                if !self.tcx().sess.has_errors().is_some() {
+                if self.tcx().sess.has_errors().is_none() {
                     span_bug!(with_expr.span, "with expression doesn't evaluate to a struct");
                 }
             }

compiler/rustc_passes/src/entry.rs

@@ -206,7 +206,7 @@ fn no_main_err(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) {
     // The file may be empty, which leads to the diagnostic machinery not emitting this
     // note. This is a relatively simple way to detect that case and emit a span-less
     // note instead.
-    let file_empty = !tcx.sess.source_map().lookup_line(sp.hi()).is_ok();
+    let file_empty = tcx.sess.source_map().lookup_line(sp.hi()).is_err();
 
     tcx.sess.emit_err(NoMainErr {
         sp,

compiler/rustc_resolve/src/ident.rs

@@ -389,7 +389,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
         }
 
-        assert!(force || !finalize.is_some()); // `finalize` implies `force`
+        assert!(force || finalize.is_none()); // `finalize` implies `force`
 
         // Make sure `self`, `super` etc produce an error when passed to here.
         if orig_ident.is_path_segment_keyword() {