[gcc r15-11571] Daily bump.

[GCC Administrator]

https://gcc.gnu.org/g:7287b1f75dab3a7ac1e335cb259c2611fced2098

commit r15-11571-g7287b1f75dab3a7ac1e335cb259c2611fced2098
Author: GCC Administrator <gccadmin@gcc.gnu.org>
Date:   Tue Sep 15 00:18:51 2026 +0000

    Daily bump.

Diff:
---
 gcc/DATESTAMP          |  2 +-
 libstdc++-v3/ChangeLog | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/gcc/DATESTAMP b/gcc/DATESTAMP
index 1c5002a42eae..1ded3e06871f 100644
--- a/gcc/DATESTAMP
+++ b/gcc/DATESTAMP
@@ -1 +1 @@
-20260914
+20260915
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 2ee9165e3ff4..013ba19f7fb0 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,50 @@
+2026-09-14  Jonathan Wakely  <jwakely@redhat.com>
+
+	Backported from master:
+	2026-09-10  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/127220
+	* include/std/format (__format::_Arg_t): Move definition
+	earlier.
+	(basic_format_parse_context::check_dynamic_spec): Construct
+	array of _Arg_t from template parameter list.
+	(basic_format_parse_context::check_dynamic_spec_integral):
+	Construct array of _Arg_t based on supported types.
+	(basic_format_parse_context::check_dynamic_spec_string):
+	Likewise.
+	(basic_format_parse_context::__check_dynamic_spec): Replace
+	template parameter list with span<const _Arg_t> function
+	parameter and simplify accordingly. Define in class body.
+	(basic_format_parse_context::_Scan_parse_context): New struct
+	the replaces _Scanner::_Parse_context.
+	(__format::_Scanner::_M_pc): Change type to _Scan_parse_context.
+
+2026-09-14  Steven Sudit  <stevensudit@gmail.com>
+
+	Backported from master:
+	2026-09-09  Steven Sudit  <stevensudit@gmail.com>
+
+	PR libstdc++/127219
+	* include/std/format
+	(basic_format_parse_context::__valid_types_for_check_dynamic_spec):
+	Make static, so that the static_assert in check_dynamic_spec does
+	not use this.
+
+2026-09-14  Tomasz Kamiński  <tkaminsk@redhat.com>
+
+	Backported from master:
+	2026-09-10  Tomasz Kamiński  <tkaminsk@redhat.com>
+		    Marco Falke  <falke.marco@gmail.com>
+
+	PR libstdc++/126949
+	* include/bits/hashtable_policy.h (_Hash_code_base::_M_hash)
+	(_Hashtable_base::_M_equal, _Hashtable_alloc::_M_alloc):
+	Value initialized members in NSDMI.
+	* testsuite/23_containers/unordered_map/cons/default.cc: Check
+	default construction with an hash, equality and allocator with
+	explicit constructor.
+	* testsuite/23_containers/unordered_set/cons/default.cc: Likewise.
+
 2026-09-07  Tomasz Kamiński  <tkaminsk@redhat.com>
 
 	Backported from master: