avoid issues when running tests via a symbolic link

tests/test_config

@@ -4,4 +4,4 @@ MACRO: CXX -cxx-c++stdlib-path share/libc++ -cxx-clang-command="bin/framaCIRGen"
 MACRO: EVA -eva -eva-msg-key=-summary
 MACRO: WP -wp -wp-par 1 -wp-session tests/wp-cache -wp-cache update -wp-msg-key shell
 OPT: @MACHDEP@ -print -check @CXX@
-FILTER:sed  -e "s|${FRAMAC_SHARE}|FRAMAC_SHARE|g" -e "s|$(pwd)/||g"
+FILTER:sed  -e "s|${FRAMAC_SHARE}|FRAMAC_SHARE|g" -e "s|$(pwd -P)/||g"