stage2: fix Cache deadlock and build more of TSAN

 * rename is_compiler_rt_or_libc to skip_linker_dependencies
   and set it to `true` for all sub-Compilations. I believe
   this resolves the deadlock we were experiencing on Drone
   CI and on some users' computers. I will remove the CI workaround in
   a follow-up commit.
 * enabling TSAN automatically causes the Compilation to link against
   libc++ even if not requested, because TSAN depends on libc++.
 * add -fno-rtti flags where appropriate when building TSAN objects.
   Thanks Firefox317 for pointing this out.
 * TSAN support: resolve all the undefined symbols. We are still seeing
   a dependency on __gcc_personality_v0 but will resolve this one in a
   follow-up commit.
 * static libs do not try to build libc++ or libc++abi.

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/tsan/interception/interception_mac.cpp b/lib/tsan/interception/interception_mac.cpp
new file mode 100644
index 0000000000..fb6eadcff5
--- /dev/null
+++ b/lib/tsan/interception/interception_mac.cpp
@@ -0,0 +1,18 @@
+//===-- interception_mac.cpp ------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Mac-specific interception methods.
+//===----------------------------------------------------------------------===//
+
+#include "interception.h"
+
+#if SANITIZER_MAC
+
+#endif  // SANITIZER_MAC