Auto merge of #69570 - Dylan-DPC:rollup-d6boczt, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #69477 (docs: add mention of async blocks in move keyword docs)
 - #69504 (Use assert_ne in hash tests)
 - #69546 (use to_vec() instead of .iter().cloned().collect() to convert slices to vecs.)
 - #69551 (use is_empty() instead of len() == x  to determine if structs are empty.)
 - #69563 (Fix no_std detection for target triples)
 - #69567 (use .to_string() instead of format!() macro to create strings)

Failed merges:

r? @ghost

src/librustc_parse/lexer/tokentrees.rs

@@ -141,7 +141,7 @@ impl<'a> TokenTreesReader<'a> {
                             self.last_delim_empty_block_spans.insert(delim, empty_block_span);
                         }
 
-                        if self.open_braces.len() == 0 {
+                        if self.open_braces.is_empty() {
                             // Clear up these spans to avoid suggesting them as we've found
                             // properly matched delimiters so far for an entire block.
                             self.matching_delim_spans.clear();

src/librustc_parse/lib.rs

@@ -371,7 +371,7 @@ fn prepend_attrs(
     span: rustc_span::Span,
 ) -> Option<tokenstream::TokenStream> {
     let tokens = tokens?;
-    if attrs.len() == 0 {
+    if attrs.is_empty() {
         return Some(tokens.clone());
     }
     let mut builder = tokenstream::TokenStreamBuilder::new();

src/librustc_parse/parser/pat.rs

@@ -216,7 +216,7 @@ impl<'a> Parser<'a> {
             .span_suggestion(
                 seq_span,
                 "...or a vertical bar to match on multiple alternatives",
-                format!("{}", seq_snippet.replace(",", " |")),
+                seq_snippet.replace(",", " |"),
                 Applicability::MachineApplicable,
             );
         }

src/librustc_parse/parser/path.rs

@@ -469,7 +469,7 @@ impl<'a> Parser<'a> {
         // FIXME: we would like to report this in ast_validation instead, but we currently do not
         // preserve ordering of generic parameters with respect to associated type binding, so we
         // lose that information after parsing.
-        if misplaced_assoc_ty_constraints.len() > 0 {
+        if !misplaced_assoc_ty_constraints.is_empty() {
             let mut err = self.struct_span_err(
                 args_lo.to(self.prev_span),
                 "associated type bindings must be declared after generic parameters",