Clarify diagnostics when using ~ as a unary op

src/libsyntax/parse/parser/expr.rs

@@ -423,7 +423,7 @@ impl<'a> Parser<'a> {
                 self.struct_span_err(span_of_tilde, "`~` cannot be used as a unary operator")
                     .span_suggestion_short(
                         span_of_tilde,
-                        "use `!` to perform bitwise negation",
+                        "use `!` to perform bitwise not",
                         "!".to_owned(),
                         Applicability::MachineApplicable
                     )

src/test/ui/did_you_mean/issue-41679-tilde-bitwise-negation-attempt.stderr

@@ -2,7 +2,7 @@ error: `~` cannot be used as a unary operator
   --> $DIR/issue-41679-tilde-bitwise-negation-attempt.rs:2:13
    |
 LL |     let x = ~1;
-   |             ^ help: use `!` to perform bitwise negation
+   |             ^ help: use `!` to perform bitwise not
 
 error: aborting due to previous error