[sanitizer] Allow Fuchsia to use getauxval
[sanitizer] Allow Fuchsia to use getauxval

Summary:
Fuchsia has `getauxval` (https://fuchsia.googlesource.com/zircon/+/master/third_party/ulib/musl/include/sys/auxv.h,
https://fuchsia.googlesource.com/zircon/+/master/third_party/ulib/musl/src/misc/getauxval.c)
so set SANITIZER_USE_GETAUXVAL to 1 for this platform.

Reviewers: alekseyshl, flowerhack

Reviewed By: flowerhack

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

Differential Revision: https://reviews.llvm.org/D42315

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@323002 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt