Fixes #2584

Better compiler errors for accessing undeclared fields, calling undeclared
procedures and procedure fields.

tests/modules/topaque.nim

@@ -1,16 +1,16 @@
 discard """
   file: "topaque.nim"
   line: 16
-  errormsg: "undeclared identifier: \'buffer\'"
+  errormsg: "undeclared field: \'buffer\'"
 """
 # Test the new opaque types
 
-import 
+import
   mopaque
-  
+
 var
   L: TLexer
-  
+
 L.filename = "ha"
 L.line = 34
 L.buffer[0] = '\0' #ERROR_MSG undeclared field: 'buffer'