Define MKCSHLIB properly for win32

configure.in

@@ -976,6 +976,7 @@ case "$target" in
     	LIB_SUFFIX=lib
     	DLL_SUFFIX=.dll
         MKSHLIB='$(LD) /NOLOGO /DLL /OUT:$@ /PDB:$(PDBFILE) $(DSO_LDOPTS)'
+        MKCSHLIB='$(LD) /NOLOGO /DLL /OUT:$@ /PDB:$(PDBFILE) $(DSO_LDOPTS)'
         MKSHLIB_FORCE_ALL=
         MKSHLIB_UNFORCE_ALL=
         DSO_LDOPTS=/SUBSYSTEM:WINDOWS