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

[Marcos Maronas via cfe-commits]

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@@ -349,13 +347,30 @@ SPIRVGlobalRegistry::getOpTypeVector(uint32_t NumElems, SPIRVTypeInst ElemType,
 
   return createConstOrTypeAtFunctionEntry(
       MIRBuilder, [&](MachineIRBuilder &MIRBuilder) {
-        return MIRBuilder.buildInstr(SPIRV::OpTypeVector)
+        return MIRBuilder
+            .buildInstr(IsLongVector ? SPIRV::OpTypeVectorIdEXT
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maarquitos14 wrote:

I'm hesitant that `IsLongVector` is the best name for this. If I read the spec correctly, a 1-element vector needs the extension. At the same time, I understand that this maps directly to the spec extension name, which is indeed `SPV_EXT_long_vector`. Maybe `IsLongVectorExt` instead?

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