parser: verilog.lex: remove \r from TK_EOL_COMMENT for DOS newlines

DOS newlines (\r\n) leak the \r character into TK_EOL_COMMENT token. If
the formatter changes the newline mode from UNIX into DOS, the original
and the formatted version will be lexically different, triggering an
error inside the VerifyFormatting

Author: IEncinas10

verible/verilog/parser/verilog.lex

@@ -294,7 +294,13 @@ PragmaEndProtected {Pragma}{Space}+protect{Space}+end_protected
     yymore();
   }
   {LineTerminator} {
-    yyless(yyleng-1);  /* return \n to input stream */
+    // This is needed in order to avoid lexical differences when the line
+    // endings are changed through verible-verilog-format. See [1]
+    // [1] https://github.com/chipsalliance/verible/pull/2371
+    if(yytext[yyleng-2] == '\r')
+      yyless(yyleng-2);  /* return \r\n to input stream */
+    else
+      yyless(yyleng-1);  /* return \n to input stream */
     UpdateLocation();
     yy_pop_state();
     return TK_EOL_COMMENT;