[llvm] [LTO] Introduce getSourceModules (NFC) (PR #105955)

[Kazu Hirata via llvm-commits]

================
@@ -352,6 +352,16 @@ void FunctionImporter::ImportMapTy::maybeAddDeclaration(
   ImportMap[FromModule].try_emplace(GUID, GlobalValueSummary::Declaration);
 }
 
+SmallVector<StringRef, 0>
+FunctionImporter::ImportMapTy::getSourceModules() const {
+  SetVector<StringRef> ModuleSet;
----------------
kazutakahirata wrote:

A good point!  I've switched to `SmallVector` in the latest iteration.  Thanks! 

https://github.com/llvm/llvm-project/pull/105955