[MLIR][LLVM] Support inlining LLVM::CallOp to LLVM::FuncOp.

Extend `LLVMInlinerInterface` to handle calls from an `LLVM::CallOp` to
an `LLVM::FuncOp` when there are no attributes present that require
special handling.

Depends on D141676

Reviewed By: gysit

Differential Revision: https://reviews.llvm.org/D141682