R600: Emit function name in the AsmPrinter

R600: Emit function name in the AsmPrinter

Emitting the function name allows us to check for it in the FileCheck
tests so we can make sure FileCheck is checking the output of the
correct function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174392 91177308-0d34-0410-b5e6-96231b3b80d8