[CBP] Pointer frontend changes + groupshared pointer support (#7848)

Resolves #7628
Resolves: #8197

Primary Goals:
1. Add `Access` to pointer
2. AddressSpace::GroupShared support for pointers (SPIR-V)
3. Add `__getAddress()` to replace `&`
* `&` is not updated to `require(cpu)` since slangpy uses `&`. This
means we must: (1) merge PR; (2) replace `&` with `__getAddress()`; (3)
add `require(cpu)` to `&`

Changes:
* Added to `Ptr` the `Access` generic argument & logic (for
`Access::Read`).
* Moved the generic argument `AddressSpace` from `Ptr` to the end of the
type.
* Added pointer casting support between any `Ptr` as long as the
`AddressSpace` is the same
* Disallow globallycoherent T* and coherent T*
* Disallow const T*, T const*, and const T*
* Fixed .natvis display of `ConstantValue` `ValOperandNode`
* Support generic resolution of type-casted integers
* Added `VariablePointer` emitting for spirv + other minor logic needed
for groupshared pointers

Breaking Changes:
* Anyone using the `AddressSpace` of `Ptr` will now have to account for
the `Access` argument
* we disallow various syntax paired with `Ptr` and `T*`

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/source/slang/slang-check-modifier.cpp b/source/slang/slang-check-modifier.cpp
index db477ac25..ebda2d637 100644
--- a/source/slang/slang-check-modifier.cpp
+++ b/source/slang/slang-check-modifier.cpp
@@ -1677,6 +1677,18 @@ Modifier* SemanticsVisitor::checkModifier(
         }
     }
 
+    if (as<ConstModifier>(m))
+    {
+        if (auto varDeclBase = as<VarDeclBase>(syntaxNode))
+        {
+            if (as<PointerTypeExpr>(varDeclBase->type.exp))
+            {
+                // Disallow `const T*` syntax.
+                getSink()->diagnose(m, Diagnostics::constNotAllowedOnCStylePtrDecl);
+                return nullptr;
+            }
+        }
+    }
     if (auto glslLayoutAttribute = as<UncheckedGLSLLayoutAttribute>(m))
     {
         return checkGLSLLayoutAttribute(glslLayoutAttribute, syntaxNode);