rename test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124993 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstSimplify/2010-12-20-Reassociate.ll b/test/Transforms/InstSimplify/reassociate.ll
similarity index 100%
rename from test/Transforms/InstSimplify/2010-12-20-Reassociate.ll
rename to test/Transforms/InstSimplify/reassociate.ll