These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.

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

Currently, `DIContext::getLineInfoForAddress` and
`DIContext::getLineInfoForDataAddress` returns empty DILineInfo when the
debug info is missing for the given address. This is not differentiable
with the case when debug info is found for the given address but the
debug info is default value (filename:linenum is <invalid>:0).

This change wraps the return types of `DIContext::getLineInfoForAddress`
and `DIContext::getLineInfoForDataAddress` with `std::optional`.

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

Identified with misc-include-cleaner.