Improve code for codeblock invalid attributes

Author: GuillaumeGomez

src/librustdoc/html/markdown.rs

@@ -1298,35 +1298,28 @@ impl LangString {
 }
 LangStringToken::LangToken(x)if extra.is_some() => {
 let s = x.to_lowercase();
-ifletSome((flag, help)) = if s == "compile-fail"
- || s == "compile_fail"
- || s == "compilefail"
-{
-Some((
+ifletSome((flag, help)) = match s.as_str(){
+"compile-fail" | "compile_fail" | "compilefail" => Some((
 "compile_fail",
-"the code block will either not be tested if not marked as a rust one \
- or won't fail if it compiles successfully",
-))
-}elseif s == "should-panic" || s == "should_panic" || s == "shouldpanic"{
-Some((
+"the code block will either not be tested if not marked as a rust \
+ one or won't fail if it compiles successfully",
+)),
+"should-panic" | "should_panic" | "shouldpanic" => Some((
 "should_panic",
-"the code block will either not be tested if not marked as a rust one \
- or won't fail if it doesn't panic when running",
-))
-}elseif s == "no-run" || s == "no_run" || s == "norun"{
-Some((
+"the code block will either not be tested if not marked as a rust \
+ one or won't fail if it doesn't panic when running",
+)),
+"no-run" | "no_run" | "norun" => Some((
 "no_run",
-"the code block will either not be tested if not marked as a rust one \
- or will be run (which you might not want)",
-))
-}elseif s == "test-harness" || s == "test_harness" || s == "testharness"{
-Some((
+"the code block will either not be tested if not marked as a rust \
+ one or will be run (which you might not want)",
+)),
+"test-harness" | "test_harness" | "testharness" => Some((
 "test_harness",
-"the code block will either not be tested if not marked as a rust one \
- or the code will be wrapped inside a main function",
-))
-}else{
-None
+"the code block will either not be tested if not marked as a rust \
+ one or the code will be wrapped inside a main function",
+)),
+ _ => None,
 }{
 ifletSome(extra) = extra {
  extra.error_invalid_codeblock_attr_with_help(