[CGP] move test file to prevent bot failures

The test specifiies the triple, so it needs to be in the
x86 directory in case a bot has been configured without
the x86 target.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352992 91177308-0d34-0410-b5e6-96231b3b80d8

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