This reapplies 85c649bc02a, which was reverted in 35767e43d62 due to failures
with some example programs. The fix was to add export_executable_symbols to the
example programs.
DFAJumpThreading
JumpThreading
LibCallsShrink
LoopVectorize
SLPVectorizer
DeadStoreElimination
AggressiveDCE
CorrelatedValuePropagation
IndVarSimplify
These are part of the optimization pipeline, of which the legacy version is deprecated and being removed.
Most notably, Pass.h is no longer included by TargetMachine.h
before: 1063570306
after: 1063332844
Differential Revision: https://reviews.llvm.org/D121168