Move catchpad-phi-cast.ll to the X86 specific subdirectory

It is X86 specific and will not be properly exercised unless LLVM is
built with the X86 target.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255426 91177308-0d34-0410-b5e6-96231b3b80d8

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