[clang] [CIR] Emit init of local variables (PR #130164)

[Henrich Lauko via cfe-commits]

================
@@ -46,21 +52,124 @@ void CIRGenFunction::emitAutoVarAlloca(const VarDecl &d) {
   address = createTempAlloca(allocaTy, alignment, loc, d.getName());
   declare(address.getPointer(), &d, ty, getLoc(d.getSourceRange()), alignment);
 
+  emission.Addr = address;
   setAddrOfLocalVar(&d, address);
+
+  return emission;
+}
+
+/// Determine whether the given initializer is trivial in the sense
+/// that it requires no code to be generated.
+bool CIRGenFunction::isTrivialInitializer(const Expr *init) {
+  if (!init)
+    return true;
+
+  if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(init))
+    if (CXXConstructorDecl *constructor = construct->getConstructor())
+      if (constructor->isTrivial() && constructor->isDefaultConstructor() &&
+          !construct->requiresZeroInitialization())
+        return true;
+
+  return false;
 }
 
-void CIRGenFunction::emitAutoVarInit(const clang::VarDecl &d) {
+void CIRGenFunction::emitAutoVarInit(
+    const CIRGenFunction::AutoVarEmission &emission) {
+  const VarDecl &d = *emission.Variable;
+
----------------
xlauko wrote:

Corresponding `CodeGenFunction::EmitAutoVarInit` has here:

```
 // If this was emitted as a global constant, we're done.
  if (emission.wasEmittedAsGlobal()) return;
```

is there any reason why this is not here for CIR?

https://github.com/llvm/llvm-project/pull/130164