Revert r302938 "Add LiveRangeShrink pass to shrink live range within BB."

This also reverts follow-ups r303292 and r303298.

It broke some Chromium tests under MSan, and apparently also internal
tests at Google.

llvm-svn: 303369

llvm/lib/CodeGen/CodeGen.cpp

@@ -43,7 +43,6 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeLiveDebugValuesPass(Registry);
   initializeLiveDebugVariablesPass(Registry);
   initializeLiveIntervalsPass(Registry);
-  initializeLiveRangeShrinkPass(Registry);
   initializeLiveStacksPass(Registry);
   initializeLiveVariablesPass(Registry);
   initializeLocalStackSlotPassPass(Registry);