[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, 19 insertions, 0 deletions

diff --git a/tests/language-feature/pointer/pointer-access/read-only-pointer-2.slang b/tests/language-feature/pointer/pointer-access/read-only-pointer-2.slang
new file mode 100644
index 000000000..c5288caba
--- /dev/null
+++ b/tests/language-feature/pointer/pointer-access/read-only-pointer-2.slang
@@ -0,0 +1,19 @@
+//TEST:SIMPLE(filecheck=CHECK):-stage compute -entry computeMain -target spirv
+
+// Tests valid use of read-only pointer
+
+// CHECK: OpEntryPoint
+// CHECK-NOT: error
+
+int* processMemory;
+int* output;
+
+typealias ReadPtr = Ptr<int, Access::Read, AddressSpace::Device>;
+
+[numthreads(1, 1, 1)]
+void computeMain(int id : SV_DispatchThreadID)
+{
+    ReadPtr ptr1 = ReadPtr(processMemory + id.x);
+
+    output[id] = ptr1[id];
+}