[clang] [CIR] Add support for delegating constructors with VTT args (PR #156970)

[Erich Keane via cfe-commits]

================
@@ -70,3 +70,266 @@ DelegatingWithZeroing::DelegatingWithZeroing(int) : DelegatingWithZeroing() {}
 // OGCG:   store i32 %[[I_ARG]], ptr %[[I_ADDR]]
 // OGCG:   %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]]
 // OGCG:   call void @llvm.memset.p0.i64(ptr align 4 %[[THIS]], i8 0, i64 4, i1 false)
+
+void other();
+
+class Base {
+public:
+  Base() { squawk(); }
+
+  virtual void squawk();
+};
+
+class Derived : public virtual Base {
+public:
+  Derived();
+  Derived(const void *inVoid);
+
+  virtual void squawk();
+};
+
+Derived::Derived() : Derived(nullptr) { other(); }
+Derived::Derived(const void *inVoid) { squawk(); }
+
+// Note: OGCG emits the constructors in a different order.
----------------
erichkeane wrote:

Ah!  Yikes, ok, sorry for the digression.  I though that was how DAG worked :(  Thank you for spending time on it, and sorry again.

https://github.com/llvm/llvm-project/pull/156970