eliminate recursive make invocation in test directory tree * test/module.mk: New file created from test/Makefile.am, test/bug-35448/module.mk, test/bug-36025/module.mk, test/bug-38236/module.mk, test/bug-38691/module.mk, test/bug-44940/module.mk, test/class-concat/module.mk, test/classdef/module.mk, test/classes/module.mk, test/ctor-vs-method/module.mk, test/fcn-handle-derived-resolution/module.mk, and test/nest/module.mk. * test/Makefile.am, test/bug-35448/module.mk, test/bug-36025/module.mk, test/bug-38236/module.mk, test/bug-38691/module.mk, test/bug-44940/module.mk, test/class-concat/module.mk, test/classdef/module.mk, test/classes/module.mk, test/ctor-vs-method/module.mk, test/fcn-handle-derived-resolution/module.mk, test/nest/module.mk: Delete. * configure.ac (AC_OUTPUT): Don't generate test/Makefile. * Makefile.am: Include test/module.mk. * build-aux/common.mk, test/build-bc-overload-tests.sh: Adapt to changes in Makefile structure.