[clang] [clang][ssaf] Integrate source-edit-generation (PR #208590)

[Ziqing Luo via cfe-commits]

================
@@ -214,6 +215,12 @@ CreateFrontendAction(CompilerInstance &CI) {
     Act = std::make_unique<ssaf::TUSummaryExtractorFrontendAction>(
         std::move(Act));
   }
+  if (!CI.getSSAFOpts().SourceTransformation.empty() ||
+      !CI.getSSAFOpts().SrcEditFile.empty() ||
+      !CI.getSSAFOpts().TransformationReportFile.empty()) {
+    Act = std::make_unique<ssaf::SourceTransformationFrontendAction>(
----------------
ziqingluo-90 wrote:

I saw
```
  /// Name of the SSAF source transformation to run. Exactly one transformation
  /// per invocation; non-empty implies the source-transformation pipeline is
  /// active.
  /// Controlled by: --ssaf-source-transformation
  std::string SourceTransformation;
```
and thought that this should be controlled solely by `!CI.getSSAFOpts().SourceTransformation.empty()`.

https://github.com/llvm/llvm-project/pull/208590