Improve configuration for dlopen and add suitable test

cfg/posix.cfg

@@ -74,6 +74,10 @@
       <not-bool/>
     </arg>
   </function>
+  <resource>
+    <alloc>dlopen</alloc>
+    <dealloc>dlclose</dealloc>
+  </resource>
   <!-- see http://pubs.opengroup.org/onlinepubs/9699919799/functions/dlopen.html -->
   <function name="dlopen">
     <noreturn>false</noreturn>
@@ -4107,4 +4111,8 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
   <podtype name="glob_t"/>
   <podtype name="locale_t"/>
   <define name="MAP_FAILED" value="-1"/>
+  <define name="RTLD_LAZY" value="0x01"/>
+  <define name="RTLD_NOW" value="0x02"/>
+  <define name="RTLD_GLOBAL" value="0x04"/>
+  <define name="RTLD_LOCAL" value="0x08"/>
 </def>

test/cfg/posix.c

@@ -12,6 +12,7 @@
 #include <dirent.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
+#include <dlfcn.h>
 #include <fcntl.h>
 // unavailable on some linux systems #include <ndbm.h>
 #include <netdb.h>
@@ -331,3 +332,19 @@ void timet_h(struct timespec* ptp1)
     // cppcheck-suppress ctime_rCalled
     ctime_r(&clock, buf);
 }
+
+void dl(const char* libname, const char* func)
+{
+    void* lib = dlopen(libname, RTLD_NOW);
+    // cppcheck-suppress resourceLeak
+    // cppcheck-suppress redundantAssignment
+    lib = dlopen(libname, RTLD_LAZY);
+    const char* funcname;
+    // cppcheck-suppress uninitvar
+    // cppcheck-suppress unreadVariable
+    void* sym = dlsym(lib, funcname);
+    void* uninit;
+    // cppcheck-suppress uninitvar
+    dlclose(uninit);
+    // cppcheck-suppress resourceLeak
+}