[asan] Avoid two compiler-synthesized calls to memset & memcpy

Otherwise the tests hang on Windows attempting to report nested errors.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D63627

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@364070 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed