Don’t use generator expression to build .pc Libs lines

When building pkg-config files, compute linker flags with a string
substitution rather than the JOIN generator expression. This ensures
that commas in linker flags don’t get treated as argument separators in
JOIN.

Bug: https://bugs.debian.org/1011294
PiperOrigin-RevId: 450675966
Change-Id: I61eacc46a468bae5ff3dae2b437a564f2f1042c2

CMake/AbseilHelpers.cmake

@@ -170,6 +170,7 @@ function(absl_cc_library)
           set(PC_CFLAGS "${PC_CFLAGS} ${cflag}")
         endif()
       endforeach()
+      string(REPLACE ";" " " PC_LINKOPTS "${ABSL_CC_LIB_LINKOPTS}")
       FILE(GENERATE OUTPUT "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc" CONTENT "\
 prefix=${CMAKE_INSTALL_PREFIX}\n\
 exec_prefix=\${prefix}\n\
@@ -181,7 +182,7 @@ Description: Abseil ${_NAME} library\n\
 URL: https://abseil.io/\n\
 Version: ${PC_VERSION}\n\
 Requires:${PC_DEPS}\n\
-Libs: -L\${libdir} $<JOIN:${ABSL_CC_LIB_LINKOPTS}, > $<$<NOT:$<BOOL:${ABSL_CC_LIB_IS_INTERFACE}>>:-labsl_${_NAME}>\n\
+Libs: -L\${libdir} ${PC_LINKOPTS} $<$<NOT:$<BOOL:${ABSL_CC_LIB_IS_INTERFACE}>>:-labsl_${_NAME}>\n\
 Cflags: -I\${includedir}${PC_CFLAGS}\n")
       INSTALL(FILES "${CMAKE_BINARY_DIR}/lib/pkgconfig/absl_${_NAME}.pc"
               DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")