[llvm] AMDGPU: Add description for amdgpu.no.access.location.types metadata (PR #85052)

[Pierre-Andre Saulais via llvm-commits]

================
@@ -1312,24 +1312,73 @@ The AMDGPU backend implements the following LLVM IR intrinsics.
 
    List AMDGPU intrinsics.
 
+.. _amdgpu_metadata:
+
 LLVM IR Metadata
-------------------
+================
+
+The AMDGPU backend implements the following target custom LLVM IR
+metadata.
+
+.. _amdgpu_last_use:
+
+'``amdgpu.last.use``' Metadata
+------------------------------
+
+Sets TH_LOAD_LU temporal hint on load instructions that support it.
+Takes priority over nontemporal hint (TH_LOAD_NT). This takes no
+arguments.
+
+.. code-block:: llvm
+
+  %val = load i32, ptr %in, align 4, !amdgpu.last.use !{}
 
-The AMDGPU backend implements the following LLVM IR metadata.
+.. _amdgpu_no_access_location_types:
 
-.. list-table:: AMDGPU LLVM IR Metatdata
-  :name: amdgpu-llvm-ir-metadata-table
+'``amdgpu.no.access.location.types``' Metadata
----------------
pasaulais wrote:

To make the name shorter, what about `amdgpu.mem.constraint` or `amdgpu.access.constraint`? Then the names of each constraint could be something like `no_fine_grained_access` and `no_remote_access` or similar.

https://github.com/llvm/llvm-project/pull/85052