[MSan] Report proper error on allocator failures instead of CHECK(0)-ing

Summary:
Following up on and complementing D44404.

Currently many allocator specific errors (OOM, for example) are reported as
a text message and CHECK(0) termination, not stack, no details, not too
helpful nor informative. To improve the situation, detailed and
structured errors were defined and reported under the appropriate conditions.

Reviewers: eugenis

Subscribers: srhines, delcypher, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D47793

llvm-svn: 334338