Show => help only if operator expected.

Author: GKFX

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -606,7 +606,9 @@ impl<'a> Parser<'a> {
             && expected.iter().any(|tok| matches!(tok, TokenType::Token(TokenKind::Gt)))
         {
             err.span_label(self.prev_token.span, "maybe try to close unmatched angle bracket");
-        } else if self.token == token::FatArrow {
+        } else if self.token == token::FatArrow
+            && expected.iter().any(|tok| matches!(tok, TokenType::Operator))
+        {
             err.help("closures are written `|a, b| a + b` and greater-than-or-equal is `>=`.");
         }
 

src/test/ui/asm/x86_64/parse-error.stderr

@@ -57,6 +57,8 @@ error: expected one of `!`, `,`, `.`, `::`, `?`, `{`, or an operator, found `=>`
    |
 LL |         asm!("{}", in(reg) foo => bar);
    |                                ^^ expected one of 7 possible tokens
+   |
+   = help: closures are written `|a, b| a + b` and greater-than-or-equal is `>=`.
 
 error: expected a path for argument to `sym`
   --> $DIR/parse-error.rs:31:24

src/test/ui/missing/missing-comma-in-match.stderr

@@ -5,6 +5,8 @@ LL |         &None => 1
    |                   - help: missing a comma here to end this `match` arm
 LL |         &Some(2) => { 3 }
    |                  ^^ expected one of `,`, `.`, `?`, `}`, or an operator
+   |
+   = help: closures are written `|a, b| a + b` and greater-than-or-equal is `>=`.
 
 error: aborting due to previous error