from Tomasz Grabiec
This series fixes lack of mutation associativity which manifests as
sporadic failures in
row_cache_test.cc::test_concurrent_reads_and_eviction due to differences
in mutations applied and read.
No known production impact.
Refs https://github.com/scylladb/scylladb/issues/11307Closes#11312
* github.com:scylladb/scylladb:
test: mutation_test: Add explicit test for mutation commutativity
test: random_mutation_generator: Workaround for non-associativity of mutations with shadowable tombstones
db: mutation_partition: Drop unnecessary maybe_shadow()
db: mutation_partition: Maintain shadowable tombstone invariant when applying a hard tombstone
mutation_partition: row: make row marker shadowing symmetric
(cherry picked from commit 484004e766)