[llvm] [mlir] [mlir][spirv] Fix int type declaration duplication when serializing (PR #145687)

[Jakub Kuderski via llvm-commits]

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@@ -5,8 +5,8 @@ if (NOT LLVM_INCLUDE_SPIRV_TOOLS_TESTS)
   return()
 endif ()
 
-if (NOT "SPIRV" IN_LIST LLVM_TARGETS_TO_BUILD)
-  message(FATAL_ERROR "Building SPIRV-Tools tests is unsupported without the SPIR-V target")
+if (NOT "SPIRV" IN_LIST LLVM_TARGETS_TO_BUILD AND NOT "mlir" IN_LIST LLVM_ENABLE_PROJECTS)
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kuhar wrote:

This looks like a hack -- we shouldn't be predicating this on what other projects are enabled. IMO, this should be a separate flag that tells cmake that spirv tools are available.

https://github.com/llvm/llvm-project/pull/145687