Use Linux 5.3 in build-many-glibcs.py

[Joseph Myers]

This patch makes build-many-glibcs.py use Linux 5.3.

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).

2019-09-17  Joseph Myers  <joseph@codesourcery.com>

	* scripts/build-many-glibcs.py (Context.checkout): Default Linux
	version to 5.3.

---

Testing was with
<https://sourceware.org/ml/libc-alpha/2019-09/msg00255.html> applied
to fix the RISC-V build.

diff --git a/scripts/build-many-glibcs.py b/scripts/build-many-glibcs.py
index cc14c7da54..b507de9f1f 100755
--- a/scripts/build-many-glibcs.py
+++ b/scripts/build-many-glibcs.py
@@ -707,7 +707,7 @@ class Context(object):
                             'gcc': 'vcs-9',
                             'glibc': 'vcs-mainline',
                             'gmp': '6.1.2',
-                            'linux': '5.2',
+                            'linux': '5.3',
                             'mpc': '1.1.0',
                             'mpfr': '4.0.2',
                             'mig': 'vcs-mainline',

-- 
Joseph S. Myers
joseph@codesourcery.com