bpo-45573: Add Modules/Setup.stdlib with conditional modules (GH-29615)

Modules/Setup.stdlib.in

@@ -0,0 +1,55 @@
+# -*- makefile -*-
+#
+# This file is autogenerated from Modules/Setup.stdlib.in.
+#
+
+# The file is not used by default yet. For testing do:
+#
+#     ln -sfr Modules/Setup.stdlib Modules/Setup.local
+#
+
+# * @MODULE_{NAME}_TRUE@ is removed when configure detects all build
+#   dependencies for a module. Otherwise the template variable is replaced
+#   by a comment "#" and the module is skipped.
+# * Module lines without any compiler and linker flags automatically use
+#   $(MODULE_{NAME}_CFLAGS) and $(MODULE_{NAME}_LDFLAGS). These flags are
+#   generated by PY_STDLIB_MOD macro.
+# * All source files automatically depend on $(PYTHON_HEADERS) and
+#   $(MODULE_{NAME}_DEPS).
+#
+# See Modules/Setup and Modules/makesetup
+#
+
+
+# Build modules statically or as shared extensions
+*shared*
+# *static*
+
+
+############################################################################
+# Modules that should always be present (POSIX and Windows):
+
+# _decimal uses libmpdec
+# either static libmpdec.a from Modules/_decimal/libmpdec or libmpdec.so
+# with ./configure --with-system-libmpdec
+@MODULE__DECIMAL_TRUE@_decimal _decimal/_decimal.c
+
+
+############################################################################
+# XML and text
+
+# pyexpat module uses libexpat
+# either static libexpat.a from Modules/expat or libexpat.so with
+# ./configure --with-system-expat
+@MODULE_PYEXPAT_TRUE@pyexpat pyexpat.c
+
+# _elementtree libexpat via CAPI hook in pyexpat.
+@MODULE__ELEMENTTREE_TRUE@_elementtree _elementtree.c
+
+
+############################################################################
+# Modules with some UNIX dependencies
+#
+
+# Linux and FreeBSD, needs sys/soundcard.h or linux/soundcard.h
+@MODULE_OSSAUDIODEV_TRUE@ossaudiodev ossaudiodev.c