Remove explicit \n and \t handling in unescape_str_common.

nnethercote · nnethercote · commit 4943142e21cb · 2023-12-07T15:53:12.000+11:00
The fallback `_` case works for these chars, no need to treat them
specially.
diff --git a/compiler/rustc_lexer/src/unescape.rs b/compiler/rustc_lexer/src/unescape.rs
@@ -350,8 +350,6 @@ where
                     _ => scan_escape::<T>(&mut chars, mode),
                 }
             }
-            '\n' => Ok(b'\n'.into()),
-            '\t' => Ok(b'\t'.into()),
             '"' => Err(EscapeError::EscapeOnlyChar),
             '\r' => Err(EscapeError::BareCarriageReturn),
             _ => ascii_check(c, mode.characters_should_be_ascii()).map(Into::into),

Original file line number	Diff line number	Diff line change
`@@ -350,8 +350,6 @@ where`
`350`	`350`	`_ => scan_escape::<T>(&mut chars, mode),`
`351`	`351`	`}`
`352`	`352`	`}`
`353`		`- '\n' => Ok(b'\n'.into()),`
`354`		`- '\t' => Ok(b'\t'.into()),`
`355`	`353`	`'"' => Err(EscapeError::EscapeOnlyChar),`
`356`	`354`	`'\r' => Err(EscapeError::BareCarriageReturn),`
`357`	`355`	`_ => ascii_check(c, mode.characters_should_be_ascii()).map(Into::into),`