[llvm] [SPIR-V] Add SPV_INTEL_2d_block_io extension (PR #140140)

[Michal Paszkowski via llvm-commits]

================
@@ -0,0 +1,47 @@
+; RUN: not llc -O0 -mtriple=spirv64-unknown-unknown %s -o %t.spvt 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_2d_block_io %s -o - | FileCheck %s
+
----------------
michalpaszkowski wrote:

Does the test pass validation with spirv-val? If it does pass, then maybe we could add this line as well: `; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s --spirv-ext=+SPV_INTEL_2d_block_io -o - -filetype=obj | spirv-val %}`. Otherwise, I would recommend adding a `TODO` line [like in this one](https://github.com/llvm/llvm-project/blob/5c3784023fcfa608d24364ca11cd688c5805a55e/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fp_const.ll#L2).

https://github.com/llvm/llvm-project/pull/140140