oeqa/selftest: test that newlib can build

Add a test to set TCLIBC=newlib and build newlib/libgloss.

This is the absolute minimum test, but at least it exercises the build
of this package.

(From OE-Core rev: cd670fd657a54601b10e9e09a40c5b51ed4d1cf8)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/newlib.py

@@ -0,0 +1,11 @@
+#
+# SPDX-License-Identifier: MIT
+#
+
+from oeqa.selftest.case import OESelftestTestCase
+from oeqa.utils.commands import bitbake
+
+class NewlibTest(OESelftestTestCase):
+    def test_newlib(self):
+        self.write_config('TCLIBC = "newlib"')
+        bitbake("newlib libgloss")