AddressSanitizer: 64-bit SPARC/Linux port

Summary:
This patch contains the bits required to make the AddressSanitizer work on SPARC64/Linux (SPARC-T4 and later).

Patch by Eric Botcazou.

Reviewers: #sanitizers, vitalybuka, krytarowski

Reviewed By: #sanitizers, vitalybuka

Subscribers: brad, vitalybuka, ro, jyknight, kubamracek, fedor.sergeev, jdoerfert, llvm-commits, #sanitizers

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D58434

llvm-svn: 355980