[RFC] Update minimum make version to 3.81

[Florian Weimer]

On 06/24/2016 06:10 PM, Mike Frysinger wrote:
> On 24 Jun 2016 13:24, Florian Weimer wrote:
>> On 06/11/2016 12:27 AM, Roland McGrath wrote:
>>> eval is a pretty horrible feature and I'd probably object to introducing
>>> any uses of it into libc's makefiles.  We already have lots of things that
>>> might have been done that way, but are instead done with generated makefiles.
>>
>> I would like to put this into malloc/Makefile:
>>
>> $(foreach t,$(tests),$(eval CFLAGS-$t.c += -DTEST_NO_MALLOPT))
>>
>> What's the alternative for adding a -D flag to every test compilation in
>> a subdirectory?
>
> maybe something like (untested):
> CPPFLAGS += $(if $(filter $(@F),$(tests)),-DTEST_NO_MALLOPT)

Hmm, right.  It's relying on the delayed expansion.  Not sure how this 
is less evil, though.  It also has at least quadratic run-time behavior.

Thanks,
Florian