[SPIR-V] Add SPIRV to LLVM_ALL_TARGETS

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: <TODO>

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-latest"]'

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/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, enabling support for 
+  SPIR-V across a range of APIs and use cases, including OpenCL, Vulkan, SYCL,
+  GLSL, and HLSL. This backend serves as a unified solution for diverse compute
+  and graphics workloads, offering a robust alternative to the Khronos SPIR-V
+  LLVM Translator.
+
 * ...
 
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