Improvements around IR representation and memory usage (#635)

* * Remove dispose from IRInst
* Use MemoryArena instead of MemoryPool
* Make all IRInst not require Dtor - by having ref counted array store ptrs that need freeing

* Increase block size - typically compilation is 2Mb of IR space(!)

* Fix issues around StringRepresentation::equal because null has special meaning.

* Don't bother to construct as String to compare StringRepresentation, just used UnownedStringSlice.

* Added fromLiteral support to UnownedStringSlice and use instead of strlen version.

* Use more conventional way to test StringRepresentation against a String.

* Fix gcc/clang template problem with cast.

1 files changed, 1 insertions, 1 deletions

diff --git a/source/slang/ir-legalize-types.cpp b/source/slang/ir-legalize-types.cpp
index 9136ad671..931ceb85a 100644
--- a/source/slang/ir-legalize-types.cpp
+++ b/source/slang/ir-legalize-types.cpp
@@ -844,7 +844,7 @@ static LegalVal legalizeInst(
 RefPtr<VarLayout> findVarLayout(IRInst* value)
 {
     if (auto layoutDecoration = value->findDecoration<IRLayoutDecoration>())
-        return layoutDecoration->layout.As<VarLayout>();
+        return layoutDecoration->layout->dynamicCast<VarLayout>();
     return nullptr;
 }