Bug fix & run overflow correction much more frequently in tests

* Fix overflow correction when `windowLog < cycleLog`. Previously, we
  got the correction wrong in this case, and our chain tables and binary
  trees would be corrupted. Now, we work as long as `maxDist` is a power
  of two, by adding `MAX(maxDist, cycleSize)` to our indices.
* When `ZSTD_WINDOW_OVERFLOW_CORRECT_FREQUENTLY` is defined to non-zero
  run overflow correction as frequently as allowed without impacting
  compression ratio.
* Enable `ZSTD_WINDOW_OVERFLOW_CORRECT_FREQUENTLY` in `fuzzer` and
  `zstreamtest` as well as all the OSS-Fuzz fuzzers. This has a 5-10%
  speed penalty at most, which seems reasonable.

lib/compress/zstd_ldm.c

@@ -500,7 +500,7 @@ size_t ZSTD_ldm_generateSequences(
 
         assert(chunkStart < iend);
         /* 1. Perform overflow correction if necessary. */
-        if (ZSTD_window_needOverflowCorrection(ldmState->window, chunkEnd)) {
+        if (ZSTD_window_needOverflowCorrection(ldmState->window, 0, maxDist, ldmState->loadedDictEnd, chunkStart, chunkEnd)) {
             U32 const ldmHSize = 1U << params->hashLog;
             U32 const correction = ZSTD_window_correctOverflow(
                 &ldmState->window, /* cycleLog */ 0, maxDist, chunkStart);