Hardware-assisted AddressSanitizer (clang part).

Summary:
Driver, frontend and LLVM codegen for HWASan.
A clone of ASan, basically.

Reviewers: kcc, pcc, alekseyshl

Subscribers: srhines, javed.absar, cfe-commits

Differential Revision: https://reviews.llvm.org/D40936

llvm-svn: 320232
diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index ca042f3..1301cdf 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -854,6 +854,8 @@
     Res |= SanitizerKind::Function;
   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsX86 || IsArmArch)
     Res |= SanitizerKind::Scudo;
+  if (IsAArch64)
+    Res |= SanitizerKind::HWAddress;
   return Res;
 }