[Sanitizer] Wrapper around llvm::DIContext from LLVM DebugInfo library. If a...

[Sanitizer] Wrapper around llvm::DIContext from LLVM DebugInfo library. If a macro SANITIZER_USES_LLVM_LIBS is defined (by default it is not), then sanitizer runtime includes llvm headers and tries to use LLVM libs for in-process symbolization. To make it functional, we have to link with these LLVM libs - either pass them to linker from Clang driver, or link them into static ASan runtime when we build it.

llvm-svn: 161045