docs(mirErr): add a description for $parse.isecfld and isecfn

docs/content/error/parse/isecfld.ngdoc

@@ -1,4 +1,18 @@
 @ngdoc error
 @name $parse:isecfld
-@fullName Referencing constructor Field
+@fullName Referencing 'constructor' Field in Expression
 @description
+
+Occurs when an expression attempts to access an objects constructor field.
+
+AngularJS bans constructor access from within expressions since constructor
+access is a known way to execute arbitrary Javascript code.
+
+To resolve this error, avoid constructor access.  As a last resort, alias
+the constructor and access it through the alias instead.
+
+Example expression that would result in this error:
+
+```
+<div>{{user.constructor.name}}</div>
+```

docs/content/error/parse/isecfn.ngdoc

@@ -2,3 +2,10 @@
 @name $parse:isecfn
 @fullName Referencing Function Disallowed
 @description
+
+Occurs when an expression attempts to access the 'Function' object.
+
+AngularJS bans access to Function from within expressions since constructor
+access is a known way to execute arbitrary Javascript code.
+
+To resolve this error, avoid Function access.