Don't add ABI-specific parameters when wrapping C

Fixes https://github.com/mono/CppSharp/issues/1008.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/Generator/Generators/CSharp/CSharpGenerator.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using CppSharp.AST;
 using CppSharp.Passes;
+using CppSharp.Parser;
 
 namespace CppSharp.Generators.CSharp
 {
@@ -36,6 +37,7 @@ namespace CppSharp.Generators.CSharp
             // CheckAbiParameters runs last because hidden structure parameters
             // should always occur first.
 
+            if (Context.ParserOptions.LanguageVersion > LanguageVersion.C99_GNU)
                 Context.TranslationUnitPasses.AddPass(new CheckAbiParameters());
 
             return true;