[libFuzzer] Don't add leaking inputs to corpus.

[kcc]

Code LG.
Please add a test.

[morehouse]

• Add test.

[kcc]

compiler-rt/test/fuzzer/fuzzer-leak.test

16 ↗

(On Diff #122290)

This is too involved. I would just run the same test with -runs=0 on the corpus.
If there are leaky inputs in the corpus that will fail.

[morehouse]

• Simplify test logic.

[kcc]

LGTM

compiler-rt/lib/fuzzer/FuzzerLoop.cpp

for (int i = 0; i < Options.MutateDepth; i++) {
     if (TotalNumberOfRuns >= Options.MaxNumberOfRuns)
       break;
     size_t NewSize = 0;
     NewSize = MD.Mutate(CurrentUnitData, Size, CurrentMaxMutationLen);
     assert(NewSize > 0 && "Mutator returned empty unit");
     assert(NewSize <= CurrentMaxMutationLen && "Mutator return oversized unit");
     Size = NewSize;
     II.NumExecutedMutations++;
-    if (RunOne(CurrentUnitData, Size, /*MayDeleteFile=*/true, &II))
-      ReportNewCoverage(&II, {CurrentUnitData, CurrentUnitData + Size});
 
+    bool NewCov = RunOne(CurrentUnitData, Size, /*MayDeleteFile=*/true, &II);
     TryDetectingAMemoryLeak(CurrentUnitData, Size,
                             /*DuringInitialCorpusExecution*/ false);
+    if (NewCov)
+      ReportNewCoverage(&II, {CurrentUnitData, CurrentUnitData + Size});
   }
 }
 
 void Fuzzer::PurgeAllocator() {
   if (Options.PurgeAllocatorIntervalSec < 0 || !EF->__sanitizer_purge_allocator)
     return;
   if (duration_cast<seconds>(system_clock::now() -
                              LastAllocatorPurgeAttemptTime)