Several fixes for handling of polymorphic variables and instanciation:

- fix the scoping of (fun ('a -> 'a -> 'a) x -> (fun ('a -> 'a) y -> ...))
so that the second interface uses the same 'a as the first
- prevent global declration of polymorphic values that are not functions (unsound
in the absence of value restriction because of side effects).
- add more complex test cases for polymorphic types and functions.
18 jobs for polymorphic in 7 minutes and 36 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Compile
passed compile_4.07.1 #679

00:00:18

passed compile_4.08.1 #680

00:00:18

passed compile_4.09.1 #681

00:00:19

passed compile_4.10.2 #682

00:00:19

passed compile_4.11.2 #683

00:00:19

passed compile_4.12.0 #684

00:00:19

 
  Test
passed test_4.07.1 #685

00:00:15

passed test_4.08.1 #686

00:00:15

passed test_4.09.1 #687

00:00:15

passed test_4.10.2 #688

00:00:15

passed test_4.11.2 #689

00:00:15

passed test_4.12.0 #690

00:00:15

 
  Package
passed package_4.07.1 #691

00:00:40

passed package_4.08.1 #692

00:00:40

passed package_4.09.1 #693

00:00:41

passed package_4.10.2 #694

00:00:41

passed package_4.11.2 #695

00:00:42

passed package_4.12.0 #696

00:00:41