[PATCH 11/16] Enable -fstack-protector=* when requested by configure.

[Nix]

On 28 Feb 2016, Andreas Schwab outgrape:

> Nix <nix@esperi.org.uk> writes:
>
>> +# We might want to compile with some stack-protection flag.
>> +ifneq ($(stack-protector),)
>> ++stack-protector=$(stack-protector)
>> +endif
>
> Why do you need that indirection?

For consistency: almost everything else added to +cflags has a
similarly-prepended name (even when it's always set to a literal
constant: e.g +merge-constants and +math-flags).

I'm happy to drop it if people think it's redundant: it's not like
$(+stack-protector) is used anywhere else.

-- 
NULL && (void)