Revert "NCG: Fix a bug in jump shortcutting."

compiler/GHC/CmmToAsm/AArch64/Instr.hs

compiler/GHC/CmmToAsm/BlockLayout.hs

compiler/GHC/CmmToAsm/Instr.hs

compiler/GHC/CmmToAsm/PPC/Instr.hs

compiler/GHC/CmmToAsm/Reg/Graph/SpillClean.hs

compiler/GHC/CmmToAsm/Reg/Linear/JoinToTargets.hs

compiler/GHC/CmmToAsm/Reg/Liveness.hs

compiler/GHC/CmmToAsm/X86/Instr.hs

testsuite/tests/codeGen/should_run/T24507.hs

testsuite/tests/codeGen/should_run/T24507.stdout

testsuite/tests/codeGen/should_run/T24507_cmm.cmm

testsuite/tests/codeGen/should_run/all.T