Redundant store instructions should be removed as dead code

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218493 91177308-0d34-0410-b5e6-96231b3b80d8
Revert patch ofr218493

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218494 91177308-0d34-0410-b5e6-96231b3b80d8
Revert patch of r218493, delete the test case

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218495 91177308-0d34-0410-b5e6-96231b3b80d8
Support: Remove undefined behavior from &raw_ostream::operator<<

Don't negate signed integer types in &raw_ostream::operator<<(const
FormattedNumber &FN).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218496 91177308-0d34-0410-b5e6-96231b3b80d8