[clang] [HLSL][SPIRV] Fix calling convention for call in entry function. (PR #110275)

[Nathan Gauër via cfe-commits]

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@@ -415,6 +415,7 @@ void CGHLSLRuntime::emitEntryFunction(const FunctionDecl *FD,
   }
 
   CallInst *CI = B.CreateCall(FunctionCallee(Fn), Args);
+  CI->setCallingConv(Fn->getCallingConv());
   (void)CI;
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Keenuts wrote:

nit: `(void)CI` can now be removed.

https://github.com/llvm/llvm-project/pull/110275