Add support for "type safety" attributes that allow checking that 'void *'

function arguments and arguments for variadic functions are of a particular
type which is determined by some other argument to the same function call.

Usecases include:
* MPI library implementations, where these attributes enable checking that
  buffer type matches the passed MPI_Datatype;
* for HDF5 library there is a similar usecase as MPI;
* checking types of variadic functions' arguments for functions like
  fcntl() and ioctl().

llvm-svn: 162067