NOTE: This is a draft

Key Changes:
1. Initializer lists call into constructors (and no longer hack around per element)
2. we auto-generate member-wise constructors for varying visibility of members (public, public-internal, public-internal-private)
3. Implements visibility and member-wise constructor rules described in shader-slang#3406
4. Reorders and reformats how we auto-generate constructors along with adding support for member-wise constructors ('visitStruct' and 'visitAggTypeDecl').
    * This was changed since currently Slang (if no constructors are found) falls back to initializer list syntax for non initializer list constructor code. Since we add a non-default-ctor this fallback logic never happens causing failures now.
5. initialization-list logic for struct objects has been reordered and reformatted due to previous logical incompatibilities.

…lG-NV/slang into initializer-list-visibility

…lG-NV/slang into initializer-list-visibility

1. fix breaking tests which cannot be fixed by adding 'old style slang array init-list syntax' support, specifically for constructing a struct without an explicit '{}'
2. clean up tests

1. resolve generics which are associated to a struct instance during init list evaluation
2. fix autodiff test with incorrect init-list

…mitations.

…lG-NV/slang into initializer-list-visibility

…rrent limitations."

Revert because it will break code, instead just check more generally for 0, if we don't want the "everything does an 'init'" logic this can be changes later.

…iures

remove all null default-ctor's like before, instead though redesign the hacky overload resolution into ctor such that it works:
1. resolveInvoke properly culls useless overloads
2. This stops spirious generation of empty init's (side-effect if we generate a real ctor)
3. This stops lots of warnings since we don't have a ctor that init's nothing

1. allow a more formalized init-list logic for flattened init-lists's
2. fixing invalid tests

1. clean-up documentation tests 2. fix recursive type crash with uninitialized value checks 3. fully disallow synth object printing rather than partially for auto-documentation code.

…for ctor

…ness bug

Adding 2 things:
1. add no_diff to synth'ed ctor if param is no_diff
2. Fix bug where DifferentialType 'ownedScope' is not setup to track the associated contained (causes 'ThisExpr' to resolve incorrectly)

member-wise synth'ed ctor's (to match how they worked when used in an init-list) check for differentiability of a member and per-member assigns no_diff appropriately.

needed to add additional inheritance-decl 'ensureDecl' to ensure we have derivative member modifiers setup correctly for correct derivative modifier annotation.

…lG-NV/slang into initializer-list-visibility

…pposed to work)

…lG-NV/slang into initializer-list-visibility

…rong'

…lG-NV/slang into initializer-list-visibility

…lG-NV/slang into initializer-list-visibility

…istFunc`; fix cudaHostModfiier assignment

…yle-partial-initializers

… 'partial-initializer-lists', disable incorrect warning (will need to look into it)

…lG-NV/slang into initializer-list-visibility

…ookup

…n style

…lG-NV/slang into initializer-list-visibility

…ializer-list-visibility

1. problem with dxil causing infinite loop (slang-ir.cpp, slang-ir-specialize-resources.cpp)

2. hlsl.meta so it doesn't use a limitation of generics that cause a crash (hlsl.meta.slang)

… emit invalid struct-value

…lG-NV/slang into initializer-list-visibility

1. move $ZeroInit definition to same pass as other functions

…nother team-member

Currently if we have a wrapped type we skip wittness table fufillment checks and try to synth an item incorrectly every-time. This is done to avoid `lookupMember()` checking inheritanceDecl's.

Since 2 levels of inheritance is not very common this caused no issues thus far.

The changes of this PR is to just lookup using `LookupOptions::IgnoreInheritance`