remove the type checking logic already done by tblgen, just keep the

remove the type checking logic already done by tblgen, just keep the
parts tblgen doesn't do (checking for constant, alloca, enclosing
function has gc marker).  This passes dj! :)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55294 91177308-0d34-0410-b5e6-96231b3b80d8