Custom linking for MinGW gives unwanted dependency on cygwin1.dll

I'm using the MinGW port of OCaml under Cygwin and trying to build a
self-contained native windows application that uses lablgtk2.  What I
find is that linking with 'ocamlc -custom' results in an executable that
depends on cygwin1.dll.  Further investigation reveals that cygwin1.dll
is being used for some math functions, and that adding '-ccopt
-L/lib/mingw' solves the problem.

For example, in the /examples directory of lablgtk2, try

	ocamlc -custom -o about.exe -I ../src lablgtk2.cma about.ml
	cygcheck ./about.exe

and see the dependency on cygwin1.dll.  Then try

	ocamlc -custom -o about.exe -I ../src lablgtk2.cma about.ml \
 		-ccopt -L/lib/mingw
	cygcheck ./about.exe

and the dependency is gone.  It must have something to do with the way
flexdll searches for libraries; other OCaml programs that don't use GTK
find the MinGW math library without problem.

I don't call this a bug, but it is something that it is useful to know
about.

Best wishes for 2009,

-- Mike