[asan] LLVM: Switch to using dynamic shadow offset on iOS

The VM layout is not stable between iOS version releases, so switch to dynamic shadow offset.

This is the LLVM counterpart of https://reviews.llvm.org/D25218

Differential Revision: https://reviews.llvm.org/D25219

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283239 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed