libsanitizer: sync from master

[Martin Liška]

Hi.

I've just pushed libsanitizer update that was tested on x86_64-linux and 
ppc64le-linux systems.
Moreover, I run bootstrap on x86_64-linux and checked ABI difference with 
abidiff.

Pushed as r13-4068-g3037f11fb86eda.

Cheers,
Martin