it's used 7 different times.
Rename `getBackEdges' to `findAndInstrumentBackEdges', for clarity.
Remove some excess whitespace and commented-out code.
Use shorter forms of CallInst ctors.
Do not make `reopt_threshold' visible to the LLVM program, and do not
pass it to the call to `reoptimizerInitialize'. Don't pass the
GlobalVariable representing it to any of our helper methods.
`reopt_threshold' is an internal parameter of the reoptimizer, which
InstLoops does not need to know about.
llvm-svn: 7794
