AddressSanitizer: fix for SPARC with GCC

Summary:
This patch contains a fixlet for the AddressSanitizer on the SPARC with GCC, which would otherwise generate a problematic call to the intercepted memcpy routine.  It was tested with GCC on SPARC/Solaris and SPARC/Linux.

Patch by Eric Botcazou.

Reviewers: #sanitizers, vitalybuka

Reviewed By: #sanitizers, vitalybuka

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

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D58433

llvm-svn: 355979