Patch to add __declspec(dllimport) to OCaml globals

Avoids:
  cannot relocate Caml_state RELOC_REL32, target is too far

+ Update Makefile to use unique repository names

Author: jonahbeckford

DEVELOPING.md

@@ -7,7 +7,7 @@ Everything in this document assumes you have done:
 make local-install
 
 # Windows
-with-dkml make local-install
+dk Ml.Use -- make local-install
 ```
 
 You may also add `--verbose` to the 'opam install' lines in the `Makefile`.

Makefile

@@ -13,8 +13,8 @@ create-switch: _opam/.opam-switch/switch-config
 #   Force an update since 'opam switch create' only updates when it newly registers the repository.
 #	Upsert (remove + add) FLEXLINKFLAGS on MSVC for debugging
 _opam/.opam-switch/switch-config:
-	opam switch create . --empty --repos diskuv=git+https://github.com/diskuv/diskuv-opam-repository.git#main,default=https://opam.ocaml.org
-	opam update diskuv
+	opam switch create . --empty --repos diskuv-main=git+https://github.com/diskuv/diskuv-opam-repository.git#main,default-main=git+https://github.com/ocaml/opam-repository.git
+	opam update diskuv-main
 	OPAMSWITCH="$$PWD" && \
 	  if [ -x /usr/bin/cygpath ]; then OPAMSWITCH=$$(/usr/bin/cygpath -aw "$$OPAMSWITCH"); fi && \
 	  if [ -n "$${COMSPEC:-}" ]; then opam option 'setenv-=FLEXLINKFLAGS+=" -link /DEBUG:FULL"'; fi

src/p/ocaml-common-4_14-a08-declspecdllimport.md

@@ -0,0 +1,12 @@
+# __declspec(dllimport)
+
+Problem on a **64-bit** Windows machine:
+
+```text
+Fatal error: cannot load shared library dllcurl_stubs
+Reason: flexdll error: cannot relocate Caml_state RELOC_REL32, target is too far: FFFFFFFF2DAA3206  000000002DAA3206
+```
+
+Confer <https://github.com/ocaml/ocaml/pull/10351#issuecomment-821957197> for the problem and solution.
+
+This patch will add `__declspec(dllimport)` to `Caml_state` and other OCaml globals if MSVC is the compiler.

src/p/ocaml-common-4_14-a08-declspecdllimport.patch

@@ -0,0 +1,13 @@
+diff --git a/runtime/caml/misc.h b/runtime/caml/misc.h
+index c605f87..43e8762 100644
+--- a/runtime/caml/misc.h
++++ b/runtime/caml/misc.h
+@@ -116,6 +116,8 @@ CAMLdeprecated_typedef(addr, char *);
+   #if defined(SUPPORT_DYNAMIC_LINKING) && defined(ARCH_SIXTYFOUR) \
+       && (defined(__CYGWIN__) || defined(__MINGW32__))
+     #define CAMLDLLIMPORT __declspec(dllimport)
++  #elif defined(SUPPORT_DYNAMIC_LINKING) && defined(_MSC_VER)
++    #define CAMLDLLIMPORT __declspec(dllimport)
+   #else
+     #define CAMLDLLIMPORT
+   #endif