Revert [CodeGen] Do the Simple Early Return in block-placement pass to optimize the blocks

This reverts r371177 (git commit f879c687)

It caused PR43566 by removing empty, address-taken MachineBasicBlocks.
Such blocks may have references from blockaddress or other operands, and
need more consideration to be removed.

See the PR for a test case to use when relanding.

llvm-svn: 373805