[ASan] Support the asan_loadN/asan_storeN functions in the DLL thunk library

Summary:
This is required for linking DLLs with large functions exceeding
san-instrumentation-with-call-threshold.  One such function is
vp9_fdct16x16_sse2 in libvpx.

Reviewers: timurrrr

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4758

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@214532 91177308-0d34-0410-b5e6-96231b3b80d8
Fix the waitid sanitizer interceptor to work on FreeBSD in 32-bit mode
Differential Revision: http://reviews.llvm.org/D4670


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@214543 91177308-0d34-0410-b5e6-96231b3b80d8
Add FreeBSD support to the address sanitizer's deep_stack_uaf.cc test case
Differential Revision: http://reviews.llvm.org/D4668


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@214544 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] Use metadata to pass source-level information from Clang to ASan.

Instead of creating global variables for source locations and global names,
just create metadata nodes and strings. They will be transformed into actual
globals in the instrumentation pass (if necessary). This approach is more
flexible:
1) we don't have to ensure that our custom globals survive all the optimizations
2) if globals are discarded for some reason, we will simply ignore metadata for them
   and won't have to erase corresponding globals
3) metadata for source locations can be reused for other purposes: e.g. we may
   attach source location metadata to alloca instructions and provide better descriptions
   for stack variables in ASan error reports.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@214604 91177308-0d34-0410-b5e6-96231b3b80d8