[llvm] Reland [SPIR-V] Support `SPV_INTEL_int4` extension (PR #141279)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-debian` running on `gribozavr4` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/16/builds/19665

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
...
PASS: LLVM :: CodeGen/SPIRV/branching/OpSwitchUnreachable.ll (20801 of 63559)
PASS: LLVM :: CodeGen/SPARC/ctpop.ll (20802 of 63559)
PASS: LLVM :: CodeGen/SPIRV/branching/Two_OpSwitch_same_register.ll (20803 of 63559)
PASS: LLVM :: CodeGen/SPARC/stack-protector.ll (20804 of 63559)
PASS: LLVM :: CodeGen/SPIRV/execution-mode-work_group_size_hint.ll (20805 of 63559)
PASS: LLVM :: CodeGen/SPARC/fp16-promote.ll (20806 of 63559)
PASS: LLVM :: CodeGen/SPIRV/branching/OpSwitchBranches.ll (20807 of 63559)
PASS: LLVM :: CodeGen/SPIRV/basic_float_types.ll (20808 of 63559)
PASS: LLVM :: CodeGen/SPIRV/const-array-in-struct.ll (20809 of 63559)
XPASS: LLVM :: CodeGen/SPIRV/constant/local-arbitrary-width-integers-constants-type-promotion.ll (20810 of 63559)
******************** TEST 'LLVM :: CodeGen/SPIRV/constant/local-arbitrary-width-integers-constants-type-promotion.ll' FAILED ********************
Exit Code: 0

Command Output (stderr):
--
/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc -O0 -mtriple=spirv32-unknown-unknown /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/SPIRV/constant/local-arbitrary-width-integers-constants-type-promotion.ll -o - | /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/SPIRV/constant/local-arbitrary-width-integers-constants-type-promotion.ll # RUN: at line 1
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc -O0 -mtriple=spirv32-unknown-unknown /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/SPIRV/constant/local-arbitrary-width-integers-constants-type-promotion.ll -o -
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/SPIRV/constant/local-arbitrary-width-integers-constants-type-promotion.ll

--

********************
PASS: LLVM :: CodeGen/SPIRV/constant/local-vector-matrix-constants.ll (20811 of 63559)
PASS: LLVM :: CodeGen/SPIRV/constant/local-aggregate-constant.ll (20812 of 63559)
PASS: LLVM :: CodeGen/SPIRV/constant/local-float-point-constants.ll (20813 of 63559)
PASS: LLVM :: CodeGen/SPIRV/constant/global-constants.ll (20814 of 63559)
PASS: LLVM :: CodeGen/SPIRV/basic_int_types.ll (20815 of 63559)
PASS: LLVM :: CodeGen/SPIRV/branching/if-merging.ll (20816 of 63559)
PASS: LLVM :: CodeGen/SPIRV/decoration-order.ll (20817 of 63559)
PASS: LLVM :: CodeGen/SPIRV/constant/local-integers-constants.ll (20818 of 63559)
PASS: LLVM :: CodeGen/SPIRV/capability-Int64Atomics.ll (20819 of 63559)
PASS: LLVM :: CodeGen/SPIRV/builtin_vars-decorate.ll (20820 of 63559)
PASS: LLVM :: CodeGen/SPIRV/assume.ll (20821 of 63559)
PASS: LLVM :: CodeGen/SPARC/float.ll (20822 of 63559)
PASS: LLVM :: CodeGen/RISCV/zmmul.ll (20823 of 63559)
PASS: LLVM :: CodeGen/SPIRV/event_no_group_cap.ll (20824 of 63559)
PASS: LLVM :: CodeGen/SPIRV/TruncToBool.ll (20825 of 63559)
PASS: LLVM :: CodeGen/SPIRV/empty-opencl32.ll (20826 of 63559)
PASS: LLVM :: CodeGen/SPIRV/empty-opencl64.ll (20827 of 63559)
PASS: LLVM :: CodeGen/SPIRV/empty-logical.ll (20828 of 63559)
XFAIL: LLVM :: CodeGen/SPIRV/EnqueueEmptyKernel.ll (20829 of 63559)
PASS: LLVM :: CodeGen/SPIRV/debug-info/debug-compilation-unit.ll (20830 of 63559)
PASS: LLVM :: CodeGen/SPIRV/execution-mode-reqd_work_group_size.ll (20831 of 63559)
PASS: LLVM :: CodeGen/SPIRV/empty.ll (20832 of 63559)
PASS: LLVM :: CodeGen/SPIRV/execution-mode-per-entry-point.ll (20833 of 63559)
PASS: LLVM :: CodeGen/SPIRV/exec_mode_float_control_khr.ll (20834 of 63559)
PASS: LLVM :: CodeGen/SPIRV/event-zero-const.ll (20835 of 63559)
PASS: LLVM :: CodeGen/SPIRV/debug-info/no-misplaced-opextinst.ll (20836 of 63559)
PASS: LLVM :: CodeGen/SPIRV/empty-module.ll (20837 of 63559)

```

</details>

https://github.com/llvm/llvm-project/pull/141279