add RT flag to prevent instantiation of GenContext

Author: Oscar Morante

Clojure/Clojure/CljCompiler/Compiler.cs

@@ -1404,7 +1404,7 @@ static GenContext CreateEvalContext(string name, bool createDynInitHelper)
             return c;
         }
 
-        static GenContext _evalContext = CreateEvalContext("eval", false);
+        static GenContext _evalContext = RuntimeBootstrapFlag.DisableEval ? null : CreateEvalContext("eval", false);
         static public GenContext EvalContext { get { return _evalContext; } }
 
         static int _saveId = 0;

Clojure/Clojure/Lib/RT.cs

@@ -3695,6 +3695,7 @@ public static class RuntimeBootstrapFlag
         /// Used in production systems when all namespaces are to be found in loaded assemblies.</remarks>
         [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2211:NonConstantFieldsShouldNotBeVisible")]
         public static bool DisableFileLoad = false;
+        public static bool DisableEval = false;
     }
 
 }