use IC.ReplaceInstUsesWith instead of a raw RAUW so that uses of
the old thing end up on the instcombine worklist.  Not doing this
can cause an extra top-level iteration of instcombine, burning
compile time.

llvm-svn: 122179
1 file changed
tree: 886ea293d0444a11e94957cff206b13fe03c9300
  1. clang/
  2. compiler-rt/
  3. debuginfo-tests/
  4. libcxx/
  5. lldb/
  6. llvm/