chore: import upstream snapshot with attribution

cmake/brpc.pc.in

@@ -0,0 +1,26 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=${prefix}
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
+
+Name: brpc
+Description: Apache bRPC is an Industrial-grade RPC framework using C++ Language, which is often used in high performance system such as Search, Storage, Machine learning, Advertisement, Recommendation etc. "bRPC" means "better RPC".
+Version: @BRPC_VERSION@
+Cflags: -I${includedir}
+Libs: -L${libdir}/ -lbrpc
+Libs.private: @BRPC_PRIVATE_LIBS@