Merge #21023: fuzz: Disable shuffle when merge=1

fabeb5b fuzz: Disable shuffle when merge=1 (MarcoFalke)

Pull request description:

  This should hopefully help make the deletion of fuzz inputs more deterministic.

  My tests (N=1) revealed that without this patch 7000 files differ (bitcoin-core/qa-assets#44 (comment)). With this patch, "only" 2000 files differ.

ACKs for top commit:
  practicalswift:
    cr ACK fabeb5b: `-shuffle=0` and `-prefer_small=1` make sense

Tree-SHA512: 21a701f52450d402a91dd6e0b33d564c63a9c3b919738eb9a80c24d48fc5b964088e325470738f39af0d595612c844acc7bf0941590cc2dc8c6f6ee4cb69c861

Author: MarcoFalke

test/fuzz/test_runner.py

@@ -225,6 +225,8 @@ def merge_inputs(*, fuzz_pool, corpus, test_list, src_dir, build_dir, merge_dir)
         args = [
             os.path.join(build_dir, 'src', 'test', 'fuzz', 'fuzz'),
             '-merge=1',
+            '-shuffle=0',
+            '-prefer_small=1',
             '-use_value_profile=1',  # Also done by oss-fuzz https://github.com/google/oss-fuzz/issues/1406#issuecomment-387790487
             os.path.join(corpus, t),
             os.path.join(merge_dir, t),