Sync coq/coqide dev packages with (safer, slower) release settings

These opam packages are currently used as templates for releases.
See discussion at ocaml/opam-repository#16908 and
ocaml/opam-repository#16876 (comment).

Only done for 8.12 and dev, which will be used in the future.

The resulting packages are safer and slower (for flambda users); fixing that
will require a more proper fix (such as ocaml/opam-repository#16887).

core-dev/packages/coq/coq.8.12.dev/opam

@@ -33,7 +33,7 @@ build: [
     "-libdir" "%{lib}%/coq"
     "-datadir" "%{share}%/coq"
     "-coqide" "no"
-    "-flambda-opts" "-O3 -unbox-closures"
+    "-native-compiler" {os = "macos"} "no" {os = "macos"}
   ]
   [make "-j%{jobs}%"]
   [make "-j%{jobs}%" "byte"]

core-dev/packages/coq/coq.dev/opam

@@ -33,7 +33,7 @@ build: [
     "-libdir" "%{lib}%/coq"
     "-datadir" "%{share}%/coq"
     "-coqide" "no"
-    "-flambda-opts" "-O3 -unbox-closures"
+    "-native-compiler" {os = "macos"} "no" {os = "macos"}
   ]
   [make "-j%{jobs}%"]
   [make "-j%{jobs}%" "byte"]

core-dev/packages/coqide/coqide.8.12.dev/opam

@@ -27,7 +27,7 @@ build: [
     "-docdir" doc
     "-libdir" "%{lib}%/coq"
     "-datadir" "%{share}%/coq"
-    "-flambda-opts" "-O3 -unbox-closures"
+    "-native-compiler" {os = "macos"} "no" {os = "macos"}
   ]
   [make "-j%{jobs}%" "coqide-files"]
   [make "-j%{jobs}%" "coqide-opt"]

core-dev/packages/coqide/coqide.dev/opam

@@ -27,7 +27,7 @@ build: [
     "-docdir" doc
     "-libdir" "%{lib}%/coq"
     "-datadir" "%{share}%/coq"
-    "-flambda-opts" "-O3 -unbox-closures"
+    "-native-compiler" {os = "macos"} "no" {os = "macos"}
   ]
   [make "-j%{jobs}%" "coqide-files"]
   [make "-j%{jobs}%" "coqide-opt"]