Add the pkg config lines back

Author: Exanite

eng/native/cmake/zig-toolchain.cmake

@@ -42,6 +42,9 @@ set(CMAKE_CXX_COMPILER "${CMAKE_CURRENT_LIST_DIR}/zig-c++${SCRIPT_SUFFIX}" -targ
 set(CMAKE_OBJCOPY "${CMAKE_CURRENT_LIST_DIR}/zig-objcopy${SCRIPT_SUFFIX}" -target ${ZIG_TARGET})
 
 if(ZIG_OS STREQUAL "linux")
+    set(PKG_CONFIG_EXECUTABLE "/usr/bin/${ZIG_ARCH}-${ZIG_OS}-${LINUX_ABI}-pkg-config")
+    set(ENV{PKG_CONFIG_LIBDIR} "/usr/lib/${ZIG_ARCH}-${ZIG_OS}-${LINUX_ABI}/pkgconfig")
+    set(ENV{PKG_CONFIG_PATH} "/usr/lib/pkgconfig:/usr/share/pkgconfig")
     set(CMAKE_LIBRARY_ARCHITECTURE "${ZIG_ARCH}-${ZIG_OS}-${LINUX_ABI}")
     set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
     set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY BOTH)