Currently, GlobalObject has an "alignment" property... but it's
basically nonsense: alignment doesn't mean the same thing for variables
and functions, and it's completely meaningless for ifuncs.

This "removes" (actually marking protected) the methods from
GlobalObject, adds the relevant methods to Function and GlobalVariable,
and adjusts the code appropriately.

This should make future alignment-related cleanups easier.

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.

- Remove calls to pass initialization from pass constructors.
- https://github.com/llvm/llvm-project/issues/111767

This reverts commit ff99af7ea03b3be46bec7203bd2b74048d29a52a.

Use nonstatic member instead. This requires explicit conversions, but
many will go away as we continue converting unsigned to Register.

In a few places where it was simple, I changed unsigned to Register.

These are the the ones where we already had a Register object being
used. Some places are still using unsigned which I did not convert.

Identified with misc-include-cleaner.

Identified with readability-redundant-control-flow.

Fixes:   https://github.com/llvm/llvm-project/issues/71030

Bug only happens in 64bit involving spills. Since we don't know when the
spill will happen, all instructions in the chain used to deduce sign
extension for eliminating 'extsw' will need to be promoted to 64-bit
pseudo instructions.

The following instruction will promoted in PPCMIPeepholes: EXTSH, LHA,
ISEL to EXTSH8, LHA8, ISEL8

Ensure registers used in instructions modified by `combineRLWINM()` are
added to list of `RegsToUpdate`.