Missing cstdint compiled with GCC 15

[liangyongxiang]

Summary

FAILED: src/lib/fcitx-utils/CMakeFiles/Fcitx5Utils.dir/inputbuffer.cpp.o
/usr/bin/x86_64-pc-linux-gnu-g++ -DFCITX_GETTEXT_DOMAIN=\"fcitx5\" -DFMT_HEADER_ONLY=1 -DFcitx5Utils_EXPORTS -I/var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10_build -I/var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10/src/lib/fcitx-utils/.. -I/var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10_build/src/lib/fcitx-utils -isystem /usr/include/dbus-1.0 -isystem /usr/lib64/dbus-1.0/include -isystem /usr/include/elogind  -Wall -Wextra -march=native -O3 -flto=jobserver -mprefer-vector-width=512 -fno-vect-cost-model -pipe -std=c++17 -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -MD -MT src/lib/fcitx-utils/CMakeFiles/Fcitx5Utils.dir/inputbuffer.cpp.o -MF src/lib/fcitx-utils/CMakeFiles/Fcitx5Utils.dir/inputbuffer.cpp.o.d -o src/lib/fcitx-utils/CMakeFiles/Fcitx5Utils.dir/inputbuffer.cpp.o -c /var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10/src/lib/fcitx-utils/inputbuffer.cpp
In file included from /var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10/src/lib/fcitx-utils/inputbuffer.cpp:7:
/var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10/src/lib/fcitx-utils/inputbuffer.h:56:15: error: ‘uint32_t’ has not been declared
   56 |     bool type(uint32_t unicode);
      |               ^~~~~~~~
/var/tmp/portage/app-i18n/fcitx-5.1.10/work/fcitx5-5.1.10/src/lib/fcitx-utils/inputbuffer.h:82:5: error: ‘uint32_t’ does not name a type
   82 |     uint32_t charAt(size_t i) const;
      |     ^~~~~~~~

Steps to Reproduce

Install GCC 15.
e.g. install gcc 15 in Gentoo and select it as the default compiler.

Expected Behavior

Compile successfully

Output of fcitx5-diagnose command

None