[PATCH] Add -Wno-error=deprecated-register to gdb build flags

[Simon Marchi <simon dot marchi at polymtl dot ca>]

As shown in PR 23022, building with clang-6 and Python 2 trips on the
fact that the Python 2 headers use the "register" keyword:

/usr/include/python2.7/unicodeobject.h:534:5: error: 'register' storage class specifier is deprecated and incompatible with C++17 [-Werror,-Wdeprecated-register]
    register PyObject *obj,     /* Object */
    ^~~~~~~~~

This patch adds -Wno-error=deprecated-register to our flags, so that we can
still see this class of warnings, but they don't cause a build failure.

gdb/ChangeLog:

	PR gdb/23022
	* warning.m4: Add -Wno-error=deprecated-register.
	* configure: Re-generate.
---
 gdb/configure  | 3 ++-
 gdb/warning.m4 | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/gdb/configure b/gdb/configure
index ab5818785333..f2acc1bf9e2c 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -15358,7 +15358,8 @@ build_warnings="-Wall -Wpointer-arith \
 -Wno-switch -Wno-char-subscripts \
 -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
 -Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized \
--Wno-mismatched-tags"
+-Wno-mismatched-tags \
+-Wno-error=deprecated-register"
 
 case "${host}" in
   *-*-mingw32*)
diff --git a/gdb/warning.m4 b/gdb/warning.m4
index ba52fb6c9ff0..3cfae65e7808 100644
--- a/gdb/warning.m4
+++ b/gdb/warning.m4
@@ -41,7 +41,8 @@ build_warnings="-Wall -Wpointer-arith \
 -Wno-switch -Wno-char-subscripts \
 -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
 -Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized \
--Wno-mismatched-tags"
+-Wno-mismatched-tags \
+-Wno-error=deprecated-register"
 
 case "${host}" in
   *-*-mingw32*)
-- 
2.16.3