!12 [sync] PR-11: Modify spec to support building with clang

From: @openeuler-sync-bot 
Reviewed-by: @wk333 
Signed-off-by: @wk333

pngquant.spec

@@ -0,0 +1,59 @@
+Name:           pngquant
+Version:        2.18.0
+Release:        2
+Summary:        PNG quantitative tool for reducing the size of the image file
+License:        GPLv3+
+URL:            http://pngquant.org
+Source0:        https://github.com/pornel/pngquant/archive/%{version}/pngquant-%{version}.tar.gz
+
+BuildRequires:  libpng-devel >= 1.2.46-1 zlib-devel >= 1.2.3-1 lcms2-devel libimagequant-devel >= %{version} gcc
+%if "%{?toolchain}" == "clang"
+BuildRequires:  libomp-devel
+%endif
+Requires:       libpng >= 1.2.46-1 zlib >= 1.2.3-1 libimagequant >= %{version}
+
+%description
+Pngquant converts a 24/32-bit RGBA PNG image into an 8-bit palette that retains the alpha channel. Such images
+are compatible with all modern web browsers and can use compatibility settings to help reduce transparency in
+Internet Explorer 6.
+
+%package        help
+Summary:        Documentation for pngquant
+
+%description    help
+This package provides documentation for pngquant.
+
+%prep
+%autosetup -n pngquant-%{version} -p1
+
+%build
+export CFLAGS="%{optflags} -fno-math-errno -funroll-loops -fomit-frame-pointer -fPIC"
+%configure --with-openmp --with-libimagequant
+%make_build
+
+%install
+%make_install
+
+%check
+%make_build test
+
+%files
+%doc README.md CHANGELOG COPYRIGHT
+%{_bindir}/%{name}
+
+%files help
+%{_mandir}/man1/%{name}.1*
+
+%changelog
+* Thu Aug 29 2024 wangqiang <wangqiang1@kylinos.cn> - 2.18.0-2
+- Support build with clang
+
+* Wed Apr 12 2023 liyanan <thistleslyn@163.com> - 2.18.0-1
+- Update to 2.18.0
+
+* Mon May 31 2021 huanghaitao <huanghaitao8@huawei.com> - 2.12.5-3
+- Completing build dependencies
+
+* Fri Dec 13 2019 fengbing <fengbing7@huawei.com> - 2.12.5-2
+- Package init
+

pngquant.yaml

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+version_control: github
+src_repo:  pornel/pngquant
+tag_prefix: ^v
+seperator: .