[clang] [llvm] [SPIRV] Add support for the `SPV_EXT_long_vector` extension (PR #210279)

[Marcos Maronas via cfe-commits]

================
@@ -0,0 +1,3606 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_EXT_long_vector --spv-allow-unknown-intrinsics=llvm. %s -o - | FileCheck %s
+; spirv-val seems to have problems reading OpTypeVectorIdEXT correctly, enable once fixed
+; TODO: %if spirv-tools %{ llc -O0 -mtriple=spirv64-amd-amdhsa --spirv-ext=+SPV_EXT_long_vector --spv-allow-unknown-intrinsics=llvm. %s -o - -filetype=obj | spirv-val %}
+
+; This is a repro extracted from IREE; once spirv-val works, testing its correct lowering into valid SPIR-V shall suffice.
----------------
maarquitos14 wrote:

Could this test be reduced? It is massive. Same for the next one.

https://github.com/llvm/llvm-project/pull/210279