[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, 17 insertions, 0 deletions

diff --git a/source/slang/slang-check-overload.cpp b/source/slang/slang-check-overload.cpp
index f949e2632..e0dbc7e08 100644
--- a/source/slang/slang-check-overload.cpp
+++ b/source/slang/slang-check-overload.cpp
@@ -1196,8 +1196,25 @@ Expr* SemanticsVisitor::CompleteOverloadCandidate(
                         {
                             // If the subscript decl has a setter,
                             // then the call is an l-value if base is l-value.
+                            //
+                            // If Ptr<T, Access> we only need to check for ReadWrite
+                            // Access (if ReadWrite result is an LValue. By default a
+                            // Ptr<...> is Read-only (unresolved generic argument & Access::Read).
                             if (auto base = GetBaseExpr(baseExpr))
                             {
+                                if (auto ptrTypeBase = as<PtrTypeBase>(base->type))
+                                {
+                                    auto accessQualifier =
+                                        as<ConstantIntVal>(ptrTypeBase->getAccessQualifier());
+                                    if (!accessQualifier ||
+                                        AccessQualifier(accessQualifier->getValue()) ==
+                                            AccessQualifier::ReadWrite)
+                                    {
+                                        callExpr->type.isLeftValue = true;
+                                    }
+                                    break;
+                                }
+
                                 if (base->type.isLeftValue)
                                 {
                                     callExpr->type.isLeftValue = true;