HIVE-11141: Improve RuleRegExp when the Expression node stack gets huge.

HIVE-11291: Avoid allocation storm while doing rule matching on operator/expression trees.

HIVE-11310: Avoid expensive AST tree conversion to String for expressions in WHERE clause.

HIVE-11311: Avoid dumping AST tree String in Explain unless necessary.

HIVE-11328: Avoid String representation of expression nodes in ConstantPropagateProcFactory unless necessary.

HIVE-11330: Add early termination for recursion in StatsRulesProcFactory.evaluateExpression.

HIVE-11397: Parse Hive OR clauses as they are written into the AST.

HIVE-11405: Add early termination for recursion in StatsRulesProcFactory.evaluateExpression for OR expression.

HIVE-11406: Vectorization: StringExpr::compare() == 0 is bad for performance.

HIVE-11981: ORC Schema Evolution Issues (Vectorized, ACID, and Non-Vectorized).

HIVE-12625: Backport to branch-1 HIVE-11981 ORC Schema Evolution Issues (Vectorized, ACID, and Non-Vectorized).

HIVE-12660: HS2 memory leak with .hiverc file use.

HIVE-12706: Incorrect output from from_utc_timestamp()/to_utc_timestamp when local timezone has DST.

HIVE-12728: Apply DDL restrictions for ORC schema evolution.

HIVE-12766: TezTask does not close DagClient after execution.

HIVE-12799: Always use Schema Evolution for ACID.