[SPARK-13890][SQL] Remove some internal classes' dependency on SQLContext

[rxin]

What changes were proposed in this pull request?

In general it is better for internal classes to not depend on the external class (in this case SQLContext) to reduce coupling between user-facing APIs and the internal implementations. This patch removes SQLContext dependency from some internal classes such as SparkPlanner, SparkOptimizer.

As part of this patch, I also removed the following internal methods from SQLContext:

protected[sql] def functionRegistry: FunctionRegistry
protected[sql] def optimizer: Optimizer
protected[sql] def sqlParser: ParserInterface
protected[sql] def planner: SparkPlanner
protected[sql] def continuousQueryManager
protected[sql] def prepareForExecution: RuleExecutor[SparkPlan]

How was this patch tested?

Existing unit/integration tests.

[rxin]

This is based on #11710

For the actual diff, just look at the last commit.

[rxin]

cc @cloud-fan

[cloud-fan]

LGTM

[SparkQA]

Test build #53161 has finished for PR 11712 at commit 31fc6cd.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class SparkOptimizer(experimentalMethods: ExperimentalMethods) extends Optimizer
  • class SparkPlanner(
  • case class CollapseCodegenStages(conf: SQLConf) extends Rule[SparkPlan]
  • case class EnsureRequirements(conf: SQLConf) extends Rule[SparkPlan]
  • case class ReuseExchange(conf: SQLConf) extends Rule[SparkPlan]
  • case class PlanSubqueries(sessionState: SessionState) extends Rule[SparkPlan]

[rxin]

Thanks - going to merge this.