fmt: fix build with GCC 9.4

fmt-native is needed to build ccache-native, and the compile fails on
hosts with GCC 9.4 (such as Ubuntu 20.04).  Backport a patch to fix this
issue.

(From OE-Core rev: 7dbb984f86d04e79d2311411cd8b775e2674b5f3)

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

meta/recipes-devtools/fmt/files/fix-gcc9.patch

@@ -0,0 +1,26 @@
+From 5f0572acdca120e11f6d810765d7a6a3c593fcbb Mon Sep 17 00:00:00 2001
+From: Victor Zverovich <viz@meta.com>
+Date: Sat, 18 Jan 2025 09:00:22 -0800
+Subject: [PATCH] Workaround a compilation error on gcc 9.4
+
+Upstream-Status: Backport [5f0572acdca120e11f6d810765d7a6a3c593fcbb]
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+---
+ include/fmt/format.h | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/include/fmt/format.h b/include/fmt/format.h
+index 9cd523a9e6a5..4466b4f4d24b 100644
+--- a/include/fmt/format.h
++++ b/include/fmt/format.h
+@@ -227,7 +227,9 @@ FMT_CONSTEXPR inline void abort_fuzzing_if(bool condition) {
+ #if defined(FMT_USE_STRING_VIEW)
+ template <typename Char> using std_string_view = std::basic_string_view<Char>;
+ #else
+-template <typename T> struct std_string_view {};
++template <typename Char> struct std_string_view {
++  operator basic_string_view<Char>() const;
++};
+ #endif
+ 
+ template <typename Char, Char... C> struct string_literal {

meta/recipes-devtools/fmt/fmt_11.1.1.bb

@@ -4,7 +4,8 @@ HOMEPAGE = "https://fmt.dev"
 LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=b9257785fc4f3803a4b71b76c1412729"
 
-SRC_URI = "git://github.com/fmtlib/fmt;branch=master;protocol=https"
+SRC_URI = "git://github.com/fmtlib/fmt;branch=master;protocol=https \
+           file://fix-gcc9.patch"
 SRCREV = "e3ddede6c4ee818825c4e5a6dfa1d384860c27d9"
 
 S = "${WORKDIR}/git"