Implement `-fvk-use-dx-layout` (#4912)

* Implement `-fvk-use-dx-layout`

Fixes: #4126

Changes:
* Added fvk-use-dx-layout
* Modified `HLSLConstantBufferLayoutRulesImpl` for correctness (ex: Array is always 16 byte aligned)
* Added kFXCShaderResourceLayoutRulesFamilyImpl and kFXCConstantBufferLayoutRulesFamilyImpl to handle fvk-use-dx-layout
* Added `ConstantBufferLayoutRules` to manage constant buffer rules
* Added `alignCompositeElementOfNonAggregate`/`alignCompositeElementOfAggregate` to handle forced alignment of composites for ConstantBuffers
* `StructuredBuffer` rules are mostly equal to `scalar` layout, not much was needed to be changed to support this behavior.

* seperate legacy constant buffer and how Slang does constant-buffer normally

* undo an addition

* remove accidental test

* Address review and fix

Address review and remove GLSL support since GLSL requires a seperate legalization (need to linearlize structs like with `legalizeMetalIR` to assign explicit offsets)

* comments

* remove aggregate and non-aggregate logic

We don't need this distinction for the logic

---------

Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/slang.h b/include/slang.h
index ea62a829f..8f4d53a0d 100644
--- a/include/slang.h
+++ b/include/slang.h
@@ -958,6 +958,7 @@ extern "C"
                                         // precompiled modules if it is up-to-date with its source.
 
             EmbedDXIL,                  // bool
+            ForceDXLayout,              // bool
             CountOf,
         };
 
@@ -4837,6 +4838,8 @@ namespace slang
         virtual SLANG_NO_THROW void SLANG_MCALL setTargetEmbedDXIL(
             int                     targetIndex,
             bool                    value) = 0;
+
+        virtual SLANG_NO_THROW void SLANG_MCALL setTargetForceDXLayout(int targetIndex, bool value) = 0;
     };
 
     #define SLANG_UUID_ICompileRequest ICompileRequest::getTypeGuid()