since it doesn't work for front-ends which don't emit column information
(which includes llvm-gcc in its present configuration), and doesn't
work for clang for K&R style variables where the variables are declared
in a different order from the parameter list.
Instead, make a separate pass through the instructions to collect the
llvm.dbg.declare instructions in order. This ensures that the debug
information for variables is emitted in this order.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108538 91177308-0d34-0410-b5e6-96231b3b80d8