[SPIR-V] Add SPIRV to LLVM_ALL_TARGETS (reapply) (#123654)

This commit promotes the SPIR-V backend from experimental to official
status. As a result, SPIR-V will be built by default, simplifying
integration and increasing accessibility for downstream projects.

Discussion and RFC on Discourse:
https://discourse.llvm.org/t/rfc-promoting-spir-v-to-an-official-target/83614

The PR reapplies the original patch
#119653, reverted due to
buildbot failures.

Author: michalpaszkowski

.github/workflows/spirv-tests.yml

@@ -25,5 +25,5 @@ jobs:
     with:
       build_target: check-llvm-codegen-spirv
       projects:
-      extra_cmake_args: '-DLLVM_TARGETS_TO_BUILD="" -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="SPIRV" -DLLVM_INCLUDE_SPIRV_TOOLS_TESTS=ON'
+      extra_cmake_args: '-DLLVM_TARGETS_TO_BUILD="SPIRV" -DLLVM_INCLUDE_SPIRV_TOOLS_TESTS=ON'
       os_list: '["ubuntu-22.04"]'

llvm/CMakeLists.txt

@@ -486,6 +486,7 @@ set(LLVM_ALL_TARGETS
   PowerPC
   RISCV
   Sparc
+  SPIRV
   SystemZ
   VE
   WebAssembly
@@ -498,7 +499,6 @@ set(LLVM_ALL_EXPERIMENTAL_TARGETS
   CSKY
   DirectX
   M68k
-  SPIRV
   Xtensa
 )
 

llvm/Maintainers.md

@@ -284,8 +284,11 @@ koachan@protonmail.com (email), [koachan](https://github.com/koachan) (GitHub)
 
 #### SPIRV backend
 
-Ilia Diachkov \
-ilia.diachkov@gmail.com (email), [iliya-diyachkov](https://github.com/iliya-diyachkov) (GitHub)
+Vyacheslav Levytskyy \
+vyacheslav.levytskyy@intel.com, vyacheslav.levytskyy@gmail.com (email), [VyacheslavLevytskyy](https://github.com/VyacheslavLevytskyy) (GitHub)
+
+Nathan Gauër \
+brioche@google.com (email), [Keenuts](https://github.com/Keenuts) (GitHub)
 
 #### SystemZ backend
 

llvm/docs/ReleaseNotes.md

@@ -47,6 +47,12 @@ for adding a new subsection. -->
   same semantics. The normalizer makes it easier to spot semantic differences
   when diffing two modules which have undergone different passes.
 
+* The SPIR-V backend is now an official LLVM target, providing OpenCL and SYCL
+  conformance and establishing a foundation for broader applicability to other
+  APIs, including Vulkan, GLSL, and HLSL. This backend aims to offer a unified
+  approach for diverse compute and graphics workloads, providing a robust
+  alternative to the Khronos SPIR-V LLVM Translator.
+
 * ...
 
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