This adds a method on the `PublicsStream` to look up symbols using their
address (segment + offset).
It's largely a reimplementation of
[`NearestSym`](https://github.com/microsoft/microsoft-pdb/blob/805655a28bd8198004be2ac27e6e0290121a5e89/PDB/dbi/gsi.cpp#L1492-L1581)
from the reference. However, we don't return the nearest symbol, but the
exact symbol.
Still, in case of ICF, we return the symbol that's first in the address
map. Users can then use the returned offset to read the next records to
check if multiple symbols overlap, if desired.

From #149701.

closes #154331 

This PR addresses all minimum changes needed to compile LLVM and MLIR
with the c++23 standard.
It is a work in progress and to be reviewed for better methods of
handling the parts of the build broken by c++23.

Mem is already of uint8_t *.

Follow-up to https://github.com/llvm/llvm-project/pull/140884

Before:

lld-link: error: Stream Error: The stream is too short to perform the requested operation.
lld-link: error: failed to write PDB file ./unit_tests.exe.pdb

After:

lld-link: error: the public (2127832912 bytes) and global (2200532960 bytes) symbols
are too large to fit in a PDB file; the maximum total is 4294967295 bytes.
lld-link: error: failed to write PDB file ./unit_tests.exe.pdb

As mentioned in the title, the missing `consumeError` triggers assertions.

Identified with misc-include-cleaner.