[llvm] annotate interfaces in llvm/IR for DLL export (#141650)

## Purpose

This patch is one in a series of code-mods that annotate LLVM’s public
interface for export. This patch annotates the `llvm/IR`,
`llvm/IRPrinter`, and `llvm/IRReader` libraries. 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).

The bulk 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 following manual adjustments were also applied after running IDS on
Linux:
- Add `#include "llvm/Support/Compiler.h"` to files where it was not
auto-added by IDS due to no pre-existing block of include statements.
- Add `LLVM_ABI_FRIEND` to friend member functions declared with
`LLVM_ABI`
- Add `LLVM_TEMPLATE_ABI` and `LLVM_EXPORT_TEMPLATE` to exported
instantiated templates
- Add `LLVM_ABI` to a subset of private class methods and fields that
require export
- Add `LLVM_ABI` to a small number of symbols that require export but
are not declared in headers
- Reorder `LLVM_ABI` with `[[deprecated]]` and `[[nodiscard]]`
attributes.

## 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

1 files changed, 6 insertions, 5 deletions

diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index eb635dc..132a8c8 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -39,6 +39,7 @@
 #include "llvm/IR/ValueSymbolTable.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CodeGen.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
@@ -53,7 +54,7 @@
 
 using namespace llvm;
 
-extern cl::opt<bool> UseNewDbgInfoFormat;
+LLVM_ABI extern cl::opt<bool> UseNewDbgInfoFormat;
 
 //===----------------------------------------------------------------------===//
 // Methods to implement the globals and functions lists.
@@ -61,10 +62,10 @@ extern cl::opt<bool> UseNewDbgInfoFormat;
 
 // Explicit instantiations of SymbolTableListTraits since some of the methods
 // are not in the public header file.
-template class llvm::SymbolTableListTraits<Function>;
-template class llvm::SymbolTableListTraits<GlobalVariable>;
-template class llvm::SymbolTableListTraits<GlobalAlias>;
-template class llvm::SymbolTableListTraits<GlobalIFunc>;
+template class LLVM_EXPORT_TEMPLATE llvm::SymbolTableListTraits<Function>;
+template class LLVM_EXPORT_TEMPLATE llvm::SymbolTableListTraits<GlobalVariable>;
+template class LLVM_EXPORT_TEMPLATE llvm::SymbolTableListTraits<GlobalAlias>;
+template class LLVM_EXPORT_TEMPLATE llvm::SymbolTableListTraits<GlobalIFunc>;
 
 //===----------------------------------------------------------------------===//
 // Primitive Module methods.