Add stdc++fs filesystem library needed for c++17 with gcc < 9

Signed-off-by: Tomasz Michalak <tmichalak@antmicro.com>

tools/CMakeLists.txt

diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 612bef1..69c5508 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -43,6 +43,8 @@
 add_executable(correlate correlate.cpp)
 add_executable(stripdb stripdb.cpp)
 set_target_properties(correlate stripdb PROPERTIES CXX_STANDARD 17)
+target_link_libraries(correlate stdc++fs)
+target_link_libraries(stripdb stdc++fs)
 
 add_executable(explain explain.cpp)
 target_link_libraries(explain common)