Cold start Improvements for Functions

#4184

This change will improve cold starts by ~30% across the board for all languages.

Here are the numbers:

					percentile_Time_taken_50	percentile_Time_taken_80	percentile_Time_taken_90	percentile_Time_taken_95	percentile_Time_taken_99	avg_Time_taken	count_
Current cold start with placeholders	2032	2250	2359	2609	3422	2111.71276595745	94
Updated cold start with placeholders and optimization	1454	1579	1734	1906	2328	1483.76470588235	119
Current cold start without placeholders 	9500	10469	11062	11453	12406	9789.04	50
Updated cold start without placeholders and optimization	6985	7859	8734	8922	9765	7208.12	50

src/WebJobs.Script.WebHost/DependencyInjection/DryIoc/Container.cs

@@ -2045,7 +2045,9 @@ public static FactoryDelegate CompileToFactoryDelegate(this Expr expression)
 #if FEC_EXPRESSION_INFO
             return lambdaExpr.ToLambdaExpression().Compile();
 #else
-            return lambdaExpr.Compile();
+            // Passing preferInterpretation: true as the default value of False uses JIT compile which has a huge impact on Functions cold start time
+            // This optimization is needed for Functions Host only and is not part of the DryIoc codebase which it was copied from.
+            return lambdaExpr.Compile(preferInterpretation: true);
 #endif
         }