Merge patch series "mcheck implementation for U-Boot"

Eugene Uriev <eugeneuriev@gmail.com> says:

There was no "mcheck" for U-Boot before.

Since U-Boot has only 1 thread, and normally makes 4000+ - 6000+
mallocs, it's better to use havier canaries to protect heap-chunks.
My variant uses 2x8 = 16byte-long protector. And
the multiplier could be changed to tune speed/protection tradeoff.
This protects not only against memset()-s, but against "near" wild
pointers too, and makes more probable to catch "distant" ones.

The core file of the set is included into the C-file, not complied
separately in order to enable (potential) coexisting of
mcheck-protectors, e.g. malloc_simple(.) and dlmalloc simultaneously.

My tests were for ARM SoC, 64bit, so the patch is
aware of alignment.

Primary this patch is for using by developers: to verify,
if a change doesn't break the heap integrity.
By default the mcheck is disabled and wouldn't affect the boot.

I used pedantic mode, canary=16byte, registry-size=6608.
For my system the overhead was 230ms.