Add virtual method `IsInlineableCallOp` to `CallInliner` to allow subclasses to change which call instructions to inline. And clean up `#include`s in `call_inliner.cc`.
Add virtual method `IsInlineableCallOp` to `CallInliner` to allow subclasses to change which call instructions to inline. And clean up `#include`s in `call_inliner.cc`.
