Apply the same Type checks for Mono

GetConstructor and GetField had the same incorrect checks order
comparing to GetMethod as in the CoreCLR.
To keep the consistent solution, Mono has also been adjusted.

src/mono/System.Private.CoreLib/src/System/Reflection/Emit/TypeBuilder.Mono.cs

@@ -1835,11 +1835,34 @@ public GenericTypeParameterBuilder[] DefineGenericParameters(params string[] nam
             return generic_params;
         }
 
+        private static bool IsValidGetMethodType(Type type)
+        {
+            if (type is TypeBuilder || type is TypeBuilderInstantiation)
+                return true;
+            /*GetMethod() must work with TypeBuilders after CreateType() was called.*/
+            if (type.Module is ModuleBuilder)
+                return true;
+            if (type.IsGenericParameter)
+                return false;
+
+            Type[] inst = type.GetGenericArguments();
+            if (inst == null)
+                return false;
+            for (int i = 0; i < inst.Length; ++i)
+            {
+                if (IsValidGetMethodType(inst[i]))
+                    return true;
+            }
+            return false;
+        }
+
         [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2070:UnrecognizedReflectionPattern",
             Justification = "Linker thinks Type.GetConstructor(ConstructorInfo) is one of the public APIs because it doesn't analyze method signatures. We already have ConstructorInfo.")]
         public static ConstructorInfo GetConstructor(Type type, ConstructorInfo constructor)
         {
-            /*FIXME I would expect the same checks of GetMethod here*/
+            if (!IsValidGetMethodType(type))
+                throw new ArgumentException("type is not TypeBuilder but " + type.GetType(), nameof(type));
+
             if (type == null)
                 throw new ArgumentException("Type is not generic", nameof(type));
 
@@ -1849,13 +1872,12 @@ public static ConstructorInfo GetConstructor(Type type, ConstructorInfo construc
             if (type.IsGenericTypeDefinition)
                 throw new ArgumentException("Type cannot be a generic type definition", nameof(type));
 
-            if (constructor == null)
-                throw new NullReferenceException(); //MS raises this instead of an ArgumentNullException
-
             if (!constructor.DeclaringType!.IsGenericTypeDefinition)
                 throw new ArgumentException("constructor declaring type is not a generic type definition", nameof(constructor));
             if (constructor.DeclaringType != type.GetGenericTypeDefinition())
                 throw new ArgumentException("constructor declaring type is not the generic type definition of type", nameof(constructor));
+            if (constructor == null)
+                throw new NullReferenceException(); //MS raises this instead of an ArgumentNullException
 
             ConstructorInfo res = type.GetConstructor(constructor);
             if (res == null)
@@ -1864,27 +1886,6 @@ public static ConstructorInfo GetConstructor(Type type, ConstructorInfo construc
             return res;
         }
 
-        private static bool IsValidGetMethodType(Type type)
-        {
-            if (type is TypeBuilder || type is TypeBuilderInstantiation)
-                return true;
-            /*GetMethod() must work with TypeBuilders after CreateType() was called.*/
-            if (type.Module is ModuleBuilder)
-                return true;
-            if (type.IsGenericParameter)
-                return false;
-
-            Type[] inst = type.GetGenericArguments();
-            if (inst == null)
-                return false;
-            for (int i = 0; i < inst.Length; ++i)
-            {
-                if (IsValidGetMethodType(inst[i]))
-                    return true;
-            }
-            return false;
-        }
-
         [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2055:UnrecognizedReflectionPattern",
             Justification = "Type.MakeGenericType is used to create a typical instantiation")]
         public static MethodInfo GetMethod(Type type, MethodInfo method)
@@ -1914,6 +1915,9 @@ public static MethodInfo GetMethod(Type type, MethodInfo method)
 
         public static FieldInfo GetField(Type type, FieldInfo field)
         {
+            if (!IsValidGetMethodType(type))
+                throw new ArgumentException("type is not TypeBuilder but " + type.GetType(), nameof(type));
+
             if (!type.IsGenericType)
                 throw new ArgumentException("Type is not a generic type", nameof(type));