[llvm] DLLExport public methods from SmallVector (PR #127850)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-adt

Author: Andrew Rogers (andrurogerz)

<details>
<summary>Changes</summary>

## Overview
Annotate the `llvm::SmallVectorBase::mallocForGrow` and `llvm::SmallVectorBase::grow_pod` methods so they are explicitly included in LLVM's public interface. When building LLVM as a Windows DLL, this annotation exports them from the DLL.

## Background
This change is required as part of the overall project to build LLVM as a Windows DLL described in #<!-- -->109483. Without this change, LLVM tools fail to link.

## Validation
Built LLVM with MSVC on Windows 11:
```
cmake -B build -S llvm -G Ninja -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN -DLLVM_BUILD_LLVM_DYLIB=ON -DLLVM_BUILD_LLVM_DYLIB_VIS=ON -DLLVM_LINK_LLVM_DYLIB=ON -DCLANG_LINK_CLANG_DYLIB=ON
ninja -C build llvm-rc llvm-ar
```
Verified the annotated interface no longer appears in the list of unresolved external symbols.

---
Full diff: https://github.com/llvm/llvm-project/pull/127850.diff


1 Files Affected:

- (modified) llvm/include/llvm/ADT/SmallVector.h (+3-3) 


``````````diff
diff --git a/llvm/include/llvm/ADT/SmallVector.h b/llvm/include/llvm/ADT/SmallVector.h
index bd3e887e36bce..cda7c1de3db2a 100644
--- a/llvm/include/llvm/ADT/SmallVector.h
+++ b/llvm/include/llvm/ADT/SmallVector.h
@@ -66,13 +66,13 @@ template <class Size_T> class SmallVectorBase {
   /// This is a helper for \a grow() that's out of line to reduce code
   /// duplication.  This function will report a fatal error if it can't grow at
   /// least to \p MinSize.
-  void *mallocForGrow(void *FirstEl, size_t MinSize, size_t TSize,
-                      size_t &NewCapacity);
+  LLVM_ABI void *mallocForGrow(void *FirstEl, size_t MinSize, size_t TSize,
+                               size_t &NewCapacity);
 
   /// This is an implementation of the grow() method which only works
   /// on POD-like data types and is out of line to reduce code duplication.
   /// This function will report a fatal error if it cannot increase capacity.
-  void grow_pod(void *FirstEl, size_t MinSize, size_t TSize);
+  LLVM_ABI void grow_pod(void *FirstEl, size_t MinSize, size_t TSize);
 
 public:
   size_t size() const { return Size; }

``````````

</details>


https://github.com/llvm/llvm-project/pull/127850