[clang-repl] Put CompilerInstance from IncrementalAction to use for non-assert/assert builds (#155400)

See
#137458 (comment)

Context: So the CompilerInstance CI being used with the Incremental
Action are tightly coupled in any case. Which means
the  CI put to use while constructing the IncrementalAction
```
  Act = TSCtx->withContextDo([&](llvm::LLVMContext *Ctx) {
    return std::make_unique<IncrementalAction>(*CI, *Ctx, ErrOut, *this,
                                               std::move(Consumer));
  });                      
```

Is also the CI through which the we call `ExecuteAction` on `Act`
```
CI->ExecuteAction(*Act);
```

So we need to use CI as a member variable in IncrementalAction for
assert builds for

https://github.com/llvm/llvm-project/blob/bddac5eda9b7591e05ccdc86a5e86c592085f318/clang/lib/Interpreter/IncrementalAction.cpp#L97-L108

The same can be put to use for `CreateASTConsumer` too as all of these
are referring to the same CI
```
std::unique_ptr<ASTConsumer>
IncrementalAction::CreateASTConsumer(CompilerInstance & /*CI*/, StringRef InFile) {
  std::unique_ptr<ASTConsumer> C =
      WrapperFrontendAction::CreateASTConsumer(this->CI, InFile);
      
```

Author: anutosh491

clang/lib/Interpreter/IncrementalAction.cpp

@@ -22,25 +22,25 @@
 #include "llvm/Support/ErrorHandling.h"
 
 namespace clang {
-IncrementalAction::IncrementalAction(CompilerInstance &CI,
+IncrementalAction::IncrementalAction(CompilerInstance &Instance,
                                      llvm::LLVMContext &LLVMCtx,
                                      llvm::Error &Err, Interpreter &I,
                                      std::unique_ptr<ASTConsumer> Consumer)
     : WrapperFrontendAction([&]() {
         llvm::ErrorAsOutParameter EAO(&Err);
         std::unique_ptr<FrontendAction> Act;
-        switch (CI.getFrontendOpts().ProgramAction) {
+        switch (Instance.getFrontendOpts().ProgramAction) {
         default:
           Err = llvm::createStringError(
               std::errc::state_not_recoverable,
               "Driver initialization failed. "
               "Incremental mode for action %d is not supported",
-              CI.getFrontendOpts().ProgramAction);
+              Instance.getFrontendOpts().ProgramAction);
           return Act;
         case frontend::ASTDump:
         case frontend::ASTPrint:
         case frontend::ParseSyntaxOnly:
-          Act = CreateFrontendAction(CI);
+          Act = CreateFrontendAction(Instance);
           break;
         case frontend::PluginAction:
         case frontend::EmitAssembly:
@@ -53,12 +53,13 @@ IncrementalAction::IncrementalAction(CompilerInstance &CI,
         }
         return Act;
       }()),
-      Interp(I), CI(CI), Consumer(std::move(Consumer)) {}
+      Interp(I), CI(Instance), Consumer(std::move(Consumer)) {}
 
 std::unique_ptr<ASTConsumer>
-IncrementalAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
+IncrementalAction::CreateASTConsumer(CompilerInstance & /*CI*/,
+                                     StringRef InFile) {
   std::unique_ptr<ASTConsumer> C =
-      WrapperFrontendAction::CreateASTConsumer(CI, InFile);
+      WrapperFrontendAction::CreateASTConsumer(this->CI, InFile);
 
   if (Consumer) {
     std::vector<std::unique_ptr<ASTConsumer>> Cs;
@@ -148,4 +149,4 @@ bool InProcessPrintingASTConsumer::HandleTopLevelDecl(DeclGroupRef DGR) {
   return MultiplexConsumer::HandleTopLevelDecl(DGR);
 }
 
-} // namespace clang
+} // namespace clang

clang/lib/Interpreter/IncrementalAction.h

@@ -42,7 +42,7 @@ class IncrementalAction : public WrapperFrontendAction {
   std::unique_ptr<llvm::Module> CachedInCodeGenModule;
 
 public:
-  IncrementalAction(CompilerInstance &CI, llvm::LLVMContext &LLVMCtx,
+  IncrementalAction(CompilerInstance &Instance, llvm::LLVMContext &LLVMCtx,
                     llvm::Error &Err, Interpreter &I,
                     std::unique_ptr<ASTConsumer> Consumer = nullptr);