Feature/initialize list side branch (#6058)

* SP004: implement initialize list translation to ctor

- We synthesize a member-wise constructor for each struct follow
   the rules described in SP004.
- Add logic to translate the initialize list to constructor invoke
- Add cuda-host decoration for the synthesized constructor
- Remove the default constructor when we have a valid member init constructor
- Disable -zero-initialize option, will re-implement it in followup (#6109).
- Fix the overload lookup issue
    When creating invoke expression for ctor, we need to call
    ResolveInvoke() to find us the best candidates, however
    the existing lookup logic could find us the base constructor
    for child struct, we should eliminate this case by providing
    the LookupOptions::IgnoreInheritance to lookup, this requires
    us to create a subcontext on SemanticsVisitor to indicate that
    we only want to use this option on looking the constructor.
- Do not implicit initialize a struct that doesn't have explicit default
   constructor.

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/autodiff/generic-constructor.slang b/tests/autodiff/generic-constructor.slang
index aad9824ec..a5b098ac2 100644
--- a/tests/autodiff/generic-constructor.slang
+++ b/tests/autodiff/generic-constructor.slang
@@ -19,6 +19,16 @@ struct Impl : IFoo
     {
         x = v.x;
     }
+
+    // We have to add this __init so that the following code can still work:
+    // Impl.Differential v0 = { (float)x };
+    // because when there is a explicit constructor defined, we will not fall back
+    // to legacy constructor. So this construction will fail.
+    [Differentiable]
+    __init(float v)
+    {
+        x = v;
+    }
 }
 
 [Differentiable]