feat!: Static linking of Grain modules (#584)

feat: Support for more WebAssembly runtimes, including Wasmtime and Wasmer
fix!: Correct type signature for `_start`
chore!: Introduce `_gmain` for old behavior of `_start`
chore!: Tail calls must be enabled explicitly via `--experimental-wasm-tail-call`
fix: Use proper return type for calls to external functions
feat: Normalized wasm exports for linked modules

compiler/dune-project

@@ -47,6 +47,18 @@
     (cmdliner (>= 1.0.2))
     (grain (>= 0))))
 
+(package
+  (name grain_linking)
+  (synopsis "The Grain linker")
+  (depends
+    (reason (>= 3.6.0))
+    (ppx_sexp_conv (>= 0.14.0))
+    (sexplib (>= 0.14.0))
+    (binaryen (= 0.9.1))
+    (ocamlgraph (>= 2.0.0))
+    (grain_utils (>= 0))
+    (grain_codegen (>= 0))))
+
 (package
   (name grain_codegen)
   (synopsis "Grain WebAssembly code generation")

compiler/esy.json

@@ -29,6 +29,7 @@
     "@opam/fp": "0.0.1",
     "@opam/fs": "0.0.2",
     "@opam/grain_dypgen": "0.2",
+    "@opam/ocamlgraph": ">= 2.0.0",
     "@opam/ppx_deriving_yojson": ">= 3.5.2",
     "@opam/ppx_expect": ">= 0.14.0",
     "@opam/ppx_sexp_conv": ">= 0.14.0",
@@ -44,6 +45,7 @@
     "@opam/ounit": ">= 2.0.0"
   },
   "resolutions": {
+    "@grain/binaryen.ml": "grain-lang/binaryen.ml#8a21a8a6ce6abad71f36e5f13492a7c7a625cb00",
     "@opam/ocamlfind": "1.8.1",
     "@opam/fp": "facebookexperimental/reason-native:fp.opam#a33f1528a6dd86c67f365e226c81312733181c87",
     "@opam/fs": "facebookexperimental/reason-native:fs.opam#a33f1528a6dd86c67f365e226c81312733181c87",