Housecleaning: move to Dune and fix compilation warnings (#2149)

* Housecleaning: move to Dune and fix compilation warnings

* Fix tests

* revert warning 9 changes

* Esy workflow

Makefile

@@ -5,7 +5,7 @@ SHELL=bash -o pipefail
 default: build
 
 build:
-	jbuilder build
+	dune build
 
 install:
 	opam pin add reason . -y
@@ -43,7 +43,7 @@ all_errors:
 # Not all versions of jbuilder have the clean command.
 # jbuilder clean
 clean: clean-tests
-	jbuilder clean
+	dune clean
 
 # The jbuilder that gets installed on CI doesn't have the make clean
 # command yet.
@@ -89,6 +89,6 @@ release: release_check pre_release
 
 all-supported-ocaml-versions:
 # the --dev flag has been omitted here but should be re-introduced eventually
-	jbuilder build @install @runtest --workspace jbuild-workspace.dev --root .
+	dune build @install @runtest --root .
 
 .PHONY: all-supported-ocaml-versions

dune-project

@@ -0,0 +1,4 @@
+(lang dune 1.1)
+
+
+(using menhir 1.0)

esy.json

@@ -13,7 +13,7 @@
     "@opam/result": "*",
     "@opam/ocaml-migrate-parsetree": "*",
     "@opam/ocamlbuild": "*",
-    "@opam/jbuilder": "*"
+    "@opam/dune": "*"
   },
   "peerDependencies": {
     "ocaml": " >= 4.2.0  < 4.7.0"
@@ -32,7 +32,7 @@
   ],
   "esy": {
     "build": [
-      [ "jbuilder", "build", "-p", "reason,rtop"]
+      [ "dune", "build", "-p", "reason,rtop"]
     ],
     "install": [
       ["esy-installer", "reason.install"],
@@ -49,7 +49,7 @@
       "@opam/result": "*",
       "@opam/ocaml-migrate-parsetree": "*",
       "@opam/ocamlbuild": "*",
-      "@opam/jbuilder": "*"
+      "@opam/dune": "*"
     }
   }
 }