When fetching allocation sizes, we almost always want to have the
size in bytes, but we were only providing an InBits API. Also add
the corresponding byte-based conjugate to save some *8 and /8
juggling everywhere.
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
C++23 will make these conversions ambiguous - so fix them to make the
codebase forward-compatible with C++23 (& a follow-up change I've made
will make this ambiguous/invalid even in <C++23 so we don't regress
this & it generally improves the code anyway)
This reverts commit 4bf69fb52b3c445ddcef5043c6b292efd14330e0.
This broke spec2k6/403.gcc under -global-isel. Details to follow once I've
reduced the problem.
