Support NativeCodeCall binding in rewrite pattern.

We are able to bind the result from native function while rewriting
pattern. In matching pattern, if we want to get some values back, we can
do that by passing parameter as return value placeholder. Besides, add
the semantic of '$_self' in NativeCodeCall while matching, it'll be the
operation that defines certain operand.

Differential Revision: https://reviews.llvm.org/D100746