This patch is activating the build of Asan on Windows 64-bits.
It's fixing compilation errors. The runtime is not yet working.

Missing features:

OverrideFunction for x64
an equiv function for inline asm (atomic_compare_exchange_strong)
shadow memory offset needs to be adjusted
RoundUpToInstrBoundary for x64
They will be implemented by subsequent patches.

Patch by Wei Wang.

Differential revision: http://reviews.llvm.org/D20455

llvm-svn: 271049