Fix a bug in default ctor synthesizing (#6527)

* Fix a bug in default ctor synthesizing

- This is fix for the implementation bug, when a struct has explicit ctor
  we should not synthesize the default ctor anymore.

- When invoke the synthesized ctor converted from initializer list, we should
  check if the struct is a c-style type if it struct has no synthesized ctor. In this
  case we should report error because it's invalid to use initializer list here.

- The only exception is the unsized array, we still have to fall back to use the
  legacy initializer list logic to initialize the unsized array until we formalize a
  proper solution.

- update test.

1 files changed, 1 insertions, 1 deletions

diff --git a/source/slang/slang-check-decl.cpp b/source/slang/slang-check-decl.cpp
index 5ee8ba3ef..34143ad75 100644
--- a/source/slang/slang-check-decl.cpp
+++ b/source/slang/slang-check-decl.cpp
@@ -12412,7 +12412,7 @@ bool SemanticsDeclAttributesVisitor::_synthesizeCtorSignature(StructDecl* struct
     // any constructors. see:
     // https://github.com/shader-slang/slang/blob/master/docs/proposals/004-initialization.md#inheritance-initialization
     if (_hasExplicitConstructor(structDecl, true))
-        return false;
+        return true;
 
     // synthesize the signature first.
     // The constructor's visibility level is the same as the struct itself.