gnulib-tool.py: Follow gnulib-tool changes, part 43. Follow gnulib-tool change 2021-06-10 Bruno Haible <bruno@clisp.org> Clarify that compiler warnings in the Gnulib tests can be ignored. * pygnulib/GLEmiter.py (GLEmiter.initmacro_start): Add boolean argument to control whether gl_CC_ALLOW_WARNINGS and gl_CXX_ALLOW_WARNINGS should be required. (GLEmiter.tests_Makefile_am): Emit overrides for CFLAGS and CXXFLAGS. Emit a dependency of 'all' on 'all-notice' that prints a warning that compiler warnings can be ignored for tests. * pygnulib/GLImport.py (GLImport.gnulib_comp): Add boolean argument to tell whether a tests Makefile.am is being emitted. Update calls to GLEmiter.initmacro_start. (GLImport.execute): Update calls to GLEmiter.initmacro_start. * pygnulib/GLTestDir.py (GLTestDir.execute): Likewise.