Fix linking errors

See:
 - protocolbuffers/protobuf#12746 (comment)
 - google/libphonenumber#3215
 - google/libphonenumber#3213

rpm/0003-cmake-absl.patch

@@ -0,0 +1,14 @@
+diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
+index b3ecc4f..7864618 100644
+--- a/cpp/CMakeLists.txt
++++ b/cpp/CMakeLists.txt
+@@ -203,7 +203,8 @@ add_custom_command (
+ )
+
+ if (${BUILD_GEOCODER} STREQUAL "ON")
+-  find_package(absl)
++  # Use "CONFIG" as there is no built-in cmake module for absl.
++  find_package(absl CONFIG REQUIRED)
+
+   # Geocoding data cpp file generation
+   set (TOOLS_DIR "${CMAKE_CURRENT_BINARY_DIR}/tools")

rpm/0004-Update-absl-dependencies-in-CMakeLists.txt

@@ -0,0 +1,13 @@
+diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
+index b3ecc4f..a35c680 100644
+--- a/cpp/CMakeLists.txt
++++ b/cpp/CMakeLists.txt
+@@ -479,7 +479,7 @@ endif ()
+ # Safeguarding against any potential link errors as mentioned in
+ # https://github.com/abseil/abseil-cpp/issues/225
+ set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
+-list (APPEND LIBRARY_DEPS absl::node_hash_set absl::strings absl::synchronization)
++list (APPEND LIBRARY_DEPS absl::node_hash_set absl::strings absl::synchronization absl::log_internal_message absl::log_internal_check_op)
+
+ if (APPLE)
+   list (APPEND COMMON_DEPS ${COREFOUNDATION_LIB} ${FOUNDATION_LIB})

rpm/libphonenumber.spec

@@ -9,6 +9,10 @@ Source0:        %{name}-%{version}.tar.gz
 # https://github.com/google/libphonenumber/pull/2556
 Patch1:         0001-Fix-geocoding-build-when-static-libraries-are-off.patch
 Patch2:         0002-Ensure-build-reproducibility.patch
+# "Backport" of https://github.com/google/libphonenumber/pull/3213
+Patch3:         0003-cmake-absl.patch
+# "Backport" of https://github.com/google/libphonenumber/pull/3215
+Patch4:         0004-Update-absl-dependencies-in-CMakeLists.txt
 
 BuildRequires:  gcc-c++
 BuildRequires:  cmake