Fix for operator assignment issue (#2951)

* WIP handling LValue coercion via LValueImplicitCast

* Need to have the ptr type for the cast.

* Casting conversion working on C++.

* Make the LValue casts record if in or in/out as we can produce better code if we know the difference.

* WIP LValueCast pass

* Fix tests so we don't fail because downstream compilers detect use of uninitialized variable.

* Do conversions through through tmp for l-value scenarios that can't work other ways.

* Fix a typo.

* Change diagnostic implicit-cast-lvalue for a type that still exhibits the issue.

* Add matrix test.

* Added a bit more clarity around LValue casting choices.

* Small comment improvements.
Improvements based on comments on PR.

* Use findOuterGeneric.

1 files changed, 7 insertions, 2 deletions

diff --git a/tests/diagnostics/implicit-cast-lvalue.slang b/tests/diagnostics/implicit-cast-lvalue.slang
index 79b619443..daf196378 100644
--- a/tests/diagnostics/implicit-cast-lvalue.slang
+++ b/tests/diagnostics/implicit-cast-lvalue.slang
@@ -1,15 +1,20 @@
 //DIAGNOSTIC_TEST:SIMPLE:
 
+
+// Generally speaking:
 // Passing an argument for an `out` parameter such
 // that implicit conversion would be required in
 // both directions.
+//
+// But we do have special case code to handle uint/int of the same type and scalar/vector/matrix forms. 
+// So for this to fail we need to use floats or something else
 
-void a(out uint x)
+void a(out float x)
 {
 	x = 0;
 }
 
-void b(int y)
+void b(double y)
 {
 	a(y);
 }