move test case to x86 directory because it specifies an x86 target

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250528 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/CodeGenPrepare/select.ll b/test/Transforms/CodeGenPrepare/X86/select.ll
similarity index 100%
rename from test/Transforms/CodeGenPrepare/select.ll
rename to test/Transforms/CodeGenPrepare/X86/select.ll