Add checks on event constructor arguments to type checker

test/contracts/bad_events.aes

@@ -0,0 +1,25 @@
+contract Events =
+  type alias_int = int
+  type alias_address = address
+  type alias_string = string
+
+  datatype event =
+      Event1(indexed alias_int, indexed int, string)
+    | Event2(alias_string, indexed alias_address)
+    | BadEvent1(indexed string, string)
+    | BadEvent2(indexed int, int)
+    | BadEvent3(indexed alias_string, string)
+    | BadEvent4(indexed int, alias_address)
+
+  function f1(x : int, y : string) =
+    Chain.event(Event1(x, x+1, y))
+
+  function f2(s : string) =
+    Chain.event(Event2(s, Call.caller))
+
+  function f3(x : int) =
+    Chain.event(Event1(x, x + 2, Int.to_str(x + 7)))
+
+  function i2s(i : int) = Int.to_str(i)
+  function a2s(a : address) = Address.to_str(a)
+

test/contracts/bad_events2.aes

@@ -0,0 +1,23 @@
+contract Events =
+  type alias_int = int
+  type alias_address = address
+  type alias_string = string
+
+  datatype event =
+      Event1(indexed alias_int, indexed int, string)
+    | Event2(alias_string, indexed alias_address)
+    | BadEvent1(string, string)
+    | BadEvent2(indexed int, indexed int, indexed int, indexed address)
+
+  function f1(x : int, y : string) =
+    Chain.event(Event1(x, x+1, y))
+
+  function f2(s : string) =
+    Chain.event(Event2(s, Call.caller))
+
+  function f3(x : int) =
+    Chain.event(Event1(x, x + 2, Int.to_str(x + 7)))
+
+  function i2s(i : int) = Int.to_str(i)
+  function a2s(a : address) = Address.to_str(a)
+

test/contracts/simple_storage.aes

@@ -18,7 +18,6 @@
 
 contract SimpleStorage =
 
-  type event = int
   record state = { data : int }
 
   function init(value : int) : state = { data = value }