[X86] Add codegen prepare test exercising a bitcast + tail call
[X86] Add codegen prepare test exercising a bitcast + tail call

In preparation of https://reviews.llvm.org/D60837, add this test where
we don't perform a tail call because we don't look through a bitcast.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@359040 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm