Log Message:
Update bash from 5.2.15 to 5.2.21 (6 new patches)

16: If an expression in an arithmetic for loop expands to NULL, the shell
    would crash.
17: In certain cases, using the `.' builtin in a subshell would optimize away
    the rest of the commands in the subshell.
18: Fix two problems with returning tokens to yyparse() when the shell
    encounters a syntax error or when it reads EOF.
19: Don't reset the terminal process group when it wasn't altered initially.
20: The parser did not allow `time' to appear as the first reserved word in a
    command substitution.
21: Fix an off-by-one error that causes command substitutions to fail when
    they appear in a word expansion inside a here-document.