enable snapshot lkm for llvm_mode persistent mode

docs/Changelog.md

@@ -31,6 +31,7 @@ sending a mail to <afl-users+subscribe@googlegroups.com>.
     - fixed crash in compare-transform-pass when strcasecmp/strncasecmp was
       tried to be instrumented with LTO
     - fixed crash in cmplog with LTO
+    - enable snapshot lkm also for persistent mode
   - persistent mode shared memory testcase handover (instead of via
     files/stdin) - 10-100% performance increase
   - General support for 64 bit PowerPC, RiscV, Sparc etc.

llvm_mode/afl-clang-fast.c

@@ -206,6 +206,8 @@ static void edit_params(u32 argc, char **argv, char **envp) {
 
   }
 
+  cc_params[cc_par_cnt++] = "-Wno-unused-command-line-argument";
+
   if (lto_mode && cpp_mode)
     cc_params[cc_par_cnt++] = "-lc++";  // needed by fuzzbench, early
 

llvm_mode/afl-llvm-rt.o.c

@@ -519,7 +519,7 @@ static void __afl_start_snapshots(void) {
 static void __afl_start_forkserver(void) {
 
 #ifdef __linux__
-  if (!is_persistent && !__afl_cmp_map && !getenv("AFL_NO_SNAPSHOT") &&
+  if (/*!is_persistent &&*/ !__afl_cmp_map && !getenv("AFL_NO_SNAPSHOT") &&
       afl_snapshot_init() >= 0) {
 
     __afl_start_snapshots();