Restore the resurrected doc link previously deleted

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174884 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64: fix build on some MSVC versions

This does two things:

It removes a call to abs() which may have "long long" parameter on Windows,
which is not necessarily available in C++03.

It also corrects the signedness of Amount, which was relying on
implementation-defined conversions previously.

Code was already tested (albeit in an implemnetation defined way) so no extra
tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174885 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] added a flag -mllvm asan-short-64bit-mapping-offset=1 (0 by default)
This flag makes asan use a small (<2G) offset for 64-bit asan shadow mapping.
On x86_64 this saves us a register, thus achieving ~2/3 of the
zero-base-offset's benefits in both performance and code size.

Thanks Jakub Jelinek for the idea.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174886 91177308-0d34-0410-b5e6-96231b3b80d8