Emit prefix data after debug and EH directives.

Emit prefix data after debug and EH directives.

This ensures that the prefix data is treated as part of the function for
the purpose of debug info.  This provides a better debugging experience,
among other things by allowing a debug info client to correctly look up
a function in debug info given a function pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193042 91177308-0d34-0410-b5e6-96231b3b80d8