tools/ocaml: silence ocaml_deprecated_auto_include alert

Ocaml's lib directory layout changed in 5.0: the unix and dynlink
libraries have been moved out of the standard library directory into
subdirectories. The compiler still locates them automatically but emits
an ocaml_deprecated_auto_include alert when doing so.

This patch sets the paths explicitly with -I +unix and -I +dynlink to
silence the alert.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@vates.tech>
Reviewed-by: Andrii Sultanov <andriy.sultanov@vates.tech>
Tested-by: Andrii Sultanov <andriy.sultanov@vates.tech>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

tools/ocaml/common.make

@@ -11,6 +11,7 @@ OCAMLFIND ?= ocamlfind
 
 CFLAGS += -fPIC -I$(shell ocamlc -where)
 
+OCAMLINCLUDE += -I +unix -I +dynlink
 OCAMLOPTFLAGS = -g -ccopt "$(LDFLAGS)" -dtypes $(OCAMLINCLUDE) -w F -warn-error F
 OCAMLCFLAGS += -g $(OCAMLINCLUDE) -w F -warn-error F