[asan] while generating the description of a global variable, emit the module...

[asan] while generating the description of a global variable, emit the module name in a separate field, thus not duplicating this information if every description. This decreases the binary size (observed up to 3%). https://code.google.com/p/address-sanitizer/issues/detail?id=168 . This changes the asan API version. compiler-rt part, llvm-part will follow

llvm-svn: 177253