Remove some dead assignements found by scan-build

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204526 91177308-0d34-0410-b5e6-96231b3b80d8
Fix the value computation in

sym_a:
sym_d = sym_a + 1

This is the smallest fix I was able to extract from what got reverted in
r204203.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204527 91177308-0d34-0410-b5e6-96231b3b80d8
Dwarf Debug: Remove some cargo-cult type uniquing. Scopes do not have
an ID, so this is a noop.
Thanks Manman for catching this!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204528 91177308-0d34-0410-b5e6-96231b3b80d8