Printing an expression is error-prone without a MCAsmInfo argument.
Remove the operator<< overload and replace callers with
MCAsmInfo::printExpr. Some callers are changed to MCExpr::print, with
the goal of eventually making it private.

so that subclasses can provide the appropriate MCAsmInfo to print
MCExpr objects.

At present, llvm/utils/TableGen/AsmMatcherEmitter.cpp constucts a
generic MCAsmInfo.

to align with targets that have made the transition.

## Purpose

This patch is one in a series of code-mods that annotate LLVM’s public
interface for export. This patch annotates the `llvm/Target` library.
These annotations currently have no meaningful impact on the LLVM build;
however, they are a prerequisite to support an LLVM Windows DLL (shared
library) build.

## Background

This effort is tracked in #109483. Additional context is provided in
[this
discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307),
and documentation for `LLVM_ABI` and related annotations is found in the
LLVM repo
[here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst).

A sub-set of these changes were generated automatically using the
[Interface Definition Scanner (IDS)](https://github.com/compnerd/ids)
tool, followed formatting with `git clang-format`.

The bulk of this change is manual additions of `LLVM_ABI` to
`LLVMInitializeX` functions defined in .cpp files under llvm/lib/Target.
Adding `LLVM_ABI` to the function implementation is required here
because they do not `#include "llvm/Support/TargetSelect.h"`, which
contains the declarations for this functions and was already updated
with `LLVM_ABI` in a previous patch. I considered patching these files
with `#include "llvm/Support/TargetSelect.h"` instead, but since
TargetSelect.h is a large file with a bunch of preprocessor x-macro
stuff in it I was concerned it would unnecessarily impact compile times.

In addition, a number of unit tests under llvm/unittests/Target required
additional dependencies to make them build correctly against the LLVM
DLL on Windows using MSVC.

## Validation

Local builds and tests to validate cross-platform compatibility. This
included llvm, clang, and lldb on the following configurations:

- Windows with MSVC
- Windows with Clang
- Linux with GCC
- Linux with Clang
- Darwin with Clang

* Use MCAsmInfo::printSpecifierExpr instead of MCExpr::print.
* Replace PPCMCExpr with MCSpecifierExpr.

Prepare for removing PPCMCExpr. Adopt the newer naming convention with
AMDGPU/WebAssembly/VE/M68k.

Many targets define MCTargetExpr subclasses just to encode an expression
with a relocation specifier. Create a generic MCSpecifierExpr to be
inherited instead. Migrate M68k and SPARC as examples.

MCAsmLexer.h has been made a forwarder header since #134207