Speedup type checking using cached overload resolution results.

This change adds caches to built-in operator overload resolution and type coersion to avoid running these time-consuming operations every time.

- Adds `TypeCheckingCache` type, which is defined in check.cpp, that contains two dictionaries for the cached results of `ResolveInvoke` and `CanCoerce` calls.
- Add `destroyTypeCheckingCache` and `getTypeCheckingCache` methods to `Session` class to reuse these cached results over the entire session.

1 files changed, 2 insertions, 0 deletions

diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index 9e740d5f5..3cb580f00 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -823,6 +823,8 @@ Session::~Session()
     irBasicBlockType = nullptr;
     constExprRate = nullptr;
 
+    destroyTypeCheckingCache();
+    
     builtinTypes = decltype(builtinTypes)();
     // destroy modules next
     loadedModuleCode = decltype(loadedModuleCode)();