This is important if the first use of a StatusOr (or Status) is in a
conditional statement, we need a stable value for `ok` from outside of
the conditional statement to make sure we don't use a different variable
in every branch.

Reviewers: jvoung, Xazax-hun

Reviewed By: jvoung

Pull Request: https://github.com/llvm/llvm-project/pull/163898

Reviewers: jvoung, Xazax-hun

Reviewed By: jvoung

Pull Request: https://github.com/llvm/llvm-project/pull/163894

This always makes the StatusOr OK.

Reviewers: jvoung, Xazax-hun

Reviewed By: jvoung

Pull Request: https://github.com/llvm/llvm-project/pull/163876

This allows comparison which these status codes

`absl::StatusOr::status` allows extraction of the status associated with
a StatusOr value. That can also be used to check whether the StatusOr
has a value or not.

This makes sure code like this is checked properly:

```cpp
int target(absl::StatusOr<int> SOR) {
  if (SOR.status().ok())
    return *SOR;
  return 0;
}
```

This reverts commit eed8d3aa4aa6efe01fcf7bd56015b671f5f18e29.

Reverts llvm/llvm-project#162932

Failed Tests (1):
  Clang-Unit :: ./AllClangUnitTests/failed_to_discover_tests_from_gtest