[CodeGen] Adding a test showing the current state of poor code gen of

search loop, by Andrey Tischenko

PR27136 shows failure to hoist constant out of loop. This test is used
as start point to fix the failure: it shows the current state of codegen
and discovers what should be fixed

Differential Revision: https://reviews.llvm.org/D25097

llvm-svn: 283091