[PATCH] build-many-glibcs.py: Add some s390x glibc variants.

[Florian Weimer]

* Stefan Liebler:

> On 8/5/20 5:39 PM, Florian Weimer wrote:
>> * Stefan Liebler via Libc-alpha:
>> 
>>> There is a s390x configure check which checks the architecture level set.
>>>
>>> This ALS influences e.g. which ifunc variants are needed or which one is
>>> the default variant or if the symbol will be an ifunc-symbol at all.
>>>
>>> The ALS also enables to use the gcc builtins for e.g. the round function
>>> in libm and others.
>>>
>>> Therefore this patch adds some glibc variants which are using different
>>> architecture level sets for s390x.
>> 
>> Do these additional build targets actually result in build breakage?

> I've run the script with those new extra-glibcs and all passed.

Sorry, this is not what I meant.  Let me rephrase.

There is some cost to adding more targets to build-many-glibcs.py.  I
think we should focus on targets where we see breakage due to generic
tree-wide changes.  This means coverage of all ABIs, and ABI variants
which have different toolchain exposure (e.g., PIE, restricted machine
code output with verification in binutils).

Or put different, if we don't see build breakage with -march=z10 like
*ever*, then it does not make sense to build a variant for this.

Thanks,
Florian