address comments

compiler/rustc_ast/src/ast.rs

@@ -1814,7 +1814,7 @@ pub enum LitKind {
     /// A byte string (`b"foo"`). Not stored as a symbol because it might be
     /// non-utf8, and symbols only allow utf8 strings.
     ByteStr(Lrc<[u8]>, StrStyle),
-    /// A C String (`c"foo"`). Guaranteed only have `\0` in the end.
+    /// A C String (`c"foo"`). Guaranteed to only have `\0` at the end.
     CStr(Lrc<[u8]>, StrStyle),
     /// A byte char (`b'f'`).
     Byte(u8),

compiler/rustc_lexer/src/lib.rs

@@ -194,7 +194,7 @@ pub enum LiteralKind {
     /// "br"abc"", "br#"abc"#", "br####"ab"###"c"####", "br#"a". `None`
     /// indicates an invalid literal.
     RawByteStr { n_hashes: Option<u8> },
-    /// `cr"abc"`, "cr#"abc"#", `cr#"a`. `None` is invalid.
+    /// `cr"abc"`, "cr#"abc"#", `cr#"a`. `None` indicates an invalid literal.
     RawCStr { n_hashes: Option<u8> },
 }