Revert "r306529 - [X86] Correct dwarf unwind information in function epilogue"

I am 99% sure that this breaks the PPC ASAN build bot:
http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/3112/steps/64-bit%20check-asan/logs/stdio

If it doesn't go back to green, we can recommit (and fix the original
commit message at the same time :) ).

llvm-svn: 306676

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -769,15 +769,8 @@ void TargetPassConfig::addMachinePasses() {
   if (getOptLevel() != CodeGenOpt::None)
     addBlockPlacement();
 
-  // Verify basic block incoming and outgoing cfa offset and register values.
-  addPass(createCFIInfoVerifier());
-
   addPreEmitPass();
 
-  // Correct CFA calculation rule where needed by inserting appropriate CFI
-  // instructions.
-  addPass(createCFIInstrInserter(), false);
-
   if (TM->Options.EnableIPRA)
     // Collect register usage information and produce a register mask of
     // clobbered registers, to be used to optimize call sites.