PR target/42811
	* libjava/configure.ac (DLLTOOL): Call AC_CHECK_TOOL.
	(libgcj_sublib_core_extra_deps): New host-dependent configure var.
	(LIBGCJ_SUBLIB_CORE_EXTRA_DEPS): AC_SUBST it.
	* libjava/configure.host (libgcj_sublib_core_extra_deps): Define
	appropriately on Cygwin and MinGW.
	(libgcj_sublib_core_extra_deps): Add libgcj-noncore-dummy import
	stub library on Cygwin and MinGW.
	* libjava/Makefile.am (LIBJAVA_CORE_EXTRA): Import AC_SUBST'd
	LIBGCJ_SUBLIB_CORE_EXTRA_DEPS if building sublibs, else define empty.
	(libgcj_la_DEPENDENCIES): Use it.
	(DLL_VERSION): New makefile macro.
	(libgcj-noncore-dummy.dll.a): New build rule for dummy import stub
	library.
	(libgcj_noncore_la_LIBADD): Trim superfluous convenience libs.
	(AM_MAKEFLAGS): Add DLLTOOL recursive propagation.
	* libjava/libgcj-noncore-dummy.def: New file.
	* libjava/Makefile.in: Regenerate.
	* libjava/include/Makefile.in: Likewise.
	* libjava/testsuite/Makefile.in: Likewise.
	* libjava/configure: Likewise.
	* libjava/gcj/Makefile.in: Likewise.

From-SVN: r157606