Mesh shader support (#2464)

* Add gdb generated files to .gitignore

* Switch to c++17

TODO: Ellie update coding style doc

* WIP mesh shaders

* Add MeshOutputType and mesh output decorations

* Lift array type layout creation out of _createTypeLayout

in preparation for sharing it elsewhere

* Initial pass at GLSL legalization for mesh shaders

* Create output types for builtin mesh outputs

This should be rendered as an out paramter block

* Handle writes to member fields in mesh shader output

* Per primitive output from mesh shaders

* Add mesh shader tests

* Redeclare mesh output builtins

* Remove unused instruction

* Emit explicit mesh output max max size

* Add unimplemented warning for array members in mesh output

* Implement mesh output splitting for GLSL in terms of getSubscriptVal

* Allow HLSL syntax for mesh output modifiers

* Improve error messages for mesh output

* Add test for HLSL style mesh output syntax

* Emit explicit mesh output indices max size

* HLSL generation support for mesh shaders

* Better errors for mesh shader misuse

* Neaten comments

* Regenerate vs2019 project files

* Fix build on vs2019

* Retreat on c++17

Will make the change in a separate PR

* slang-glslang binary dep 11.10.0 -> 11.12.0-32

* Fixes for msvc compiler

* Update msvc project

1 files changed, 9 insertions, 1 deletions

diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index 2478eccc2..cd5f58925 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -24,6 +24,7 @@
 #include "slang-ir-insts.h"
 #include "slang-ir-inline.h"
 #include "slang-ir-legalize-array-return-type.h"
+#include "slang-ir-legalize-mesh-outputs.h"
 #include "slang-ir-legalize-varying-params.h"
 #include "slang-ir-link.h"
 #include "slang-ir-com-interface.h"
@@ -680,7 +681,7 @@ Result linkAndOptimizeIR(
             session,
             irModule,
             irEntryPoints,
-            codeGenContext->getSink(),
+            codeGenContext,
             glslExtensionTracker);
 
 #if 0
@@ -774,6 +775,13 @@ Result linkAndOptimizeIR(
 
     cleanUpVoidType(irModule);
 
+    // For some small improvement in type safety we represent these as opaque
+    // structs instead of regular arrays.
+    //
+    // If any have survived this far, change them back to regular (decorated)
+    // arrays that the emitters can deal with.
+    legalizeMeshOutputTypes(irModule);
+
     // Lower all bit_cast operations on complex types into leaf-level
     // bit_cast on basic types.
     lowerBitCast(targetRequest, irModule);