Fix make call in Cygwin environment

Author: kit-ty-kate

src/c/dune

@@ -25,7 +25,8 @@
     "sh configure --host `ocamlc -config | awk '/host/ {print $NF}'` \
       'CC=%{cc}' CFLAGS=-DNDEBUG --silent --enable-silent-rules")
    (ignore-outputs (bash
-    "%{make} V=0 -j 4 -o aclocal.m4 -o Makefile.in -o configure \
+    "$([ '%{os_type}' = Unix ] && echo %{make} || echo make) V=0 -j 4 \
+      -o aclocal.m4 -o Makefile.in -o configure \
       -o configure.status -o Makefile libuv.la"))
    (ignore-outputs (bash
     "sh libtool --silent --no-warnings --mode install cp libuv.la `pwd`"))))